Marxist conspiracy

Singapore Infopedia


In May 1987, the Ministry of Home Affairs arrested 16 people under the Internal Security Act (ISA) for their involvement in a “Marxist conspiracy”. They were detained without trial for between one month and three years. Tan Wah Piow, a former University of Singapore Students’ Union president residing in the United Kingdom, was named the mastermind behind the plot.1

The 16 people who were arrested were Vincent Cheng Kim Chuan, Teo Soh Lung, Kevin de Souza, Wong Souk Yee, Tang Lay Lee, Ng Bee Leng, Jenny Chin Lai Ching, Kenneth Tsang Chi Seng, Chung Lai Mei, Mah Lee Lin, Low Yit Leng, Tan Tee Seng, Teresa Lim Li Kok, Chia Boon Tai, Tay Hong Seng and William Yap Hon Ngian.2

The mostly English-educated group was a mix of church workers, social workers, graduates and professionals who were arrested and accused of being part of a “Marxist conspiracy” to topple the government. Their intention was to “subvert Singapore’s political and social order using communist united front tactics”.3

The government named Tan Wah Piow, a former University of Singapore Students’ Union president based in the United Kingdom as the mastermind behind the plot. Tan had left Singapore in 1976 after evading National Service.4

Vincent Cheng, a full-time church volunteer, was Tan’s key assistant. They shared a common goal of establishing a classless society. Cheng, who once studied to be a Catholic priest, concentrated on two main areas: church groups and students via the student union, especially those from the Singapore Polytechnic. The strategy was to use the church in their political struggle. During small Bible study sessions, Cheng and his members spread anti-establishment ideas.5

The government listed church organisations that it believed were used to further the Marxist cause. This included the Justice and Peace Commission, of which Cheng was the executive secretary, the Student Christian Movement of Singapore, the Young Christian Workers Movement and the Catholic Welfare Centre, which assisted foreign workers and maids working in Singapore.6

It was also said that the detainees had links with Filipino leftists and advocates of “liberation theology” as well as Sri Lankan separatists.7 Liberation theology was reportedly a movement in Roman Catholic religious teaching advocating for the Church’s active involvement in combating social, political and economic oppression.8

Over a few weeks after the initial arrest in May 1987, six more people were arrested which brought the total under arrest to 22 people.9 Following the arrest, Catholic priests Fathers Edgar D’Souza and Patrick Goh issued statements questioning the detentions. Church services were held for the detainees and their families, and this contributed to the build-up of tension between the Church and the government.10

A meeting was arranged between Prime Minister Lee Kuan Yew and Archbishop Gregory Yong, who heads the Catholic Church in Singapore, and several other Catholic Church representatives. Lee’s prime concern was that there should not be any conflict between the Church and the State because of the arrests.11

The group were shown documents relating to Cheng, which included letters, and meeting notes in Cheng’s handwriting. Archbishop Yong said that he accepted the Internal Security Department’s evidence against Cheng and was convinced that the government had nothing against the Catholic Church when they arrested him. Lee stressed that the government upheld freedom of religion but will not tolerate the use of religion for subversive activities.12

In a move to avoid conflict, Fathers Joseph Ho, Patrick Goh, Edgar D’Souza and Guillaume Arotcarena resigned from all positions in church organisations. Archbishop Yong later suspended them from their preaching duties and warned the clergy not to mix politics and religion. He also announced that the Catholic Centre for Foreign Workers would be shut down.13

A few weeks after his arrest, Cheng was interviewed by local journalists in a televised programme titled Vincent Cheng and the Marxist Network.14 He spoke of how he had become interested in the idea of a classless society and class struggle after reading Maoist literature that Tan had given him. He also revealed that he used the Catholic Church and various church bodies and publications because they provided a ready cover to further the cause. Cheng said that Tan wanted him to build a broad base of grassroots organisations that could be used to build political action against the government through means such as demonstrations, strikes and riots.15 The strategy was aimed at “confronting the Government, creating turmoil in the country, agitating the masses, so that in creating instability, the government of the day can be overthrown”.16 Cheng expressed regret using the church institutions and manipulating the young people who trusted him.17

Tan’s role in the Marxist plot was evident in the letters that he wrote to Chia Boon Tai. The letters were not sent to Chia directly but were instead addressed to Chia’s brother in Johor Baru. In the letters, Tan suggested using the church’s support and goodwill to further their cause.18

Cheng was served with a two-year detention order. Eleven others, including Teo Soh Lung, were served with one-year detention orders. Six more people were arrested while some of the detainees were released.

In a two-part television documentary titled Tracing the Conspiracy, the detainees spoke of the roles they played in an intricate network. Tang Lay Lee and Teo revealed how they targeted the Law Society as a pressure group to oppose the government. Wong Souk Yee spoke of how the drama group, Third Stage, used plays as a tool to portray Singapore’s social and political system in an unfavourable light. Tan also insisted that they infiltrate the Workers’ Party, and on his insistence the group helped to print and distribute Workers’ Party pamphlets during the 1984 General Elections. After the elections, Kenneth Tsang Chi Seng and Tan Tee Seng slowly moved into positions of influence within the party. They later took control of the party’s publication, The Hammer, which they used as a channel to propagate anti-government sentiments and influence public opinion against the government.19

By December 1987, all the detainees had been released except for Cheng.

In April 1988, nine of the released detainees issued a joint statement accusing the government of ill treatment and torture while under detention. They also denied involvement in any conspiracy and alleged that they were pressured to make the confessions.20 Eight of the nine were re-arrested and detained for a second time. The ninth member, Tang, escaped re-arrest as she was in the United Kingdom.21

The government took these charges seriously and announced that a Commission of Inquiry would be set up. The detainees later made statutory declarations retracting their previous allegations. The Commission of Inquiry was called off. It was subsequently revealed that the statement was a political ploy to discredit the government and damage its integrity.22

Four of the detainees – Teo, Tsang, Wong Souk Yee and Kevin de Souza were issued with one-year detention orders. They filed for writ of habeas corpus proceedings. A habeas corpus is a legal action or writ, through which a person can seek release from the unlawful detention of himself, or of another person.23

Queens Counsel Anthony Lester pleaded Teo’s case but the application was dismissed by the High Court. She later filed an appeal.24 Lester was later banned from working in Singapore because the government said that he had started meddling in domestic politics.25

The Court of Appeal ordered the four detainees to be released but they were immediately re-arrested under new detention orders. The detainees filed fresh applications for writ of habeas corpus. However, three of the detainees later withdrew their applications and they were released. Teo’s application was dismissed by the High Court and she filed an appeal again.

Soon after the Court of Appeals decision, amendments were made to the Internal Security Act to tighten the law.

The detention orders for Teo and Cheng were extended for one year. Cheng filed a writ of habeas corpus, and his case came before Justice Lai Kew Chai but was dismissed with costs.26 Teo’s appeal against the High Court decision was heard in the Court of Appeal. She was released in early June 1990.27

After being under detention for three years, Cheng was conditionally released in mid-June 1990. He had to abide by six restrictive conditions, one of which was not to engage or get involved in any activity that advocated a political cause.28

Impact on laws
In January 1989, the Internal Security Act was amended to remove the power of the judiciary in cases related to internal security. Appeals to the Privy Council were also abolished because the government inferred that only the local courts should be involved in matters that involved Singapore’s national security.29

The Maintenance of Religious Harmony Act became law in1992, giving the Minister for Home Affairs the power to issue restraining orders against any religious leader whose sermons, speeches or actions threaten Singapore’s religious harmony.30

Libel suit
In 1989 Lee sued and won a libel suit against the Far Eastern Economic Review for an article that the magazine published regarding the meeting between him and Archbishop Yong.

May 1987
: 16 persons are arrested under the ISA. Government says detainees are involved in a Marxist conspiracy.

Jun 1987: Lee meets Archbishop Yong and Catholic leaders. Four of the original 16 detainees are released. Six more people are arrested.
Sep 1987: Teo and six others are freed.
Dec 1987: All detainees freed except for Cheng.
Apr 1988: Nine detainees issue statement denying involvement in Marxist plot and alleging ill-treatment while under detention. Eight are re-arrested. Teo files writ of habeas corpus.
Jun 1988: Four more detainees freed. Teo, Tsang, Wong and Kevin de Souza are issued with one-year detention orders. They begin habeas corpus proceedings.
Aug 1988: Teo’s habeas corpus dismissed. She files appeal to Court of Appeal.
Sep 1988: Appeal is heard.
Dec 1988: Court of Appeal orders four detainees released but are re-arrested immediately.
Feb 1989: Two more detainees freed.
Mar 1989: New writ of habeas corpus hearing on Teo’s re-detention. Three other detainees withdraw their writs and are released.
Apr 1989: Teo’s habeas corpus application is dismissed. She appeals.
Jun 1989: Detention orders for Teo and Cheng extended for one year. Cheng files writ of habeas corpus.
Feb 1990: Cheng’s application is dismissed.
Apr 1990: Teo’s appeal is dismissed.
Jun 1990: Teo and Cheng are released.
Feb 2011: Ex- detainees Michael Fernandez and Vincent Cheng join the Singapore Democratic Party.
May 2017: Ex-detainees launch the book 1987: Singapore's Marxist Conspiracy 30 Years onto mark the 30th anniversary of the 1987 arrests and call to abolish the ISA.33

Jagjit Kaur

1. “16 Held in Security Swoop,” Straits Times, 22 May 1987, 1. (From NewspaperSG)
2. “Those Who Were Arrested,” Straits Times, 27 May 1987, 14. (From NewspaperSG)
3.  “Red Threat Is Still Real,” Straits Times, 27 May 1987, 15. (From NewspaperSG)
4. “Two Main Fronts in Conspiracy,” Straits Times, 27 May 1987, 14. (From NewspaperSG)
5.  “Poly Was Infiltrated Via Student Union,” Straits Times, 27 May 1987, 15. (From NewspaperSG)
6.  “How Church Was Used as Cover for Subversion,” Straits Times, 29 May 1987, 16. (From NewspaperSG)
7.  Paul Martin, “Pacific Reds Get Hands on Funds Raised By Churches for the Poor,” Straits Times, 18 July 1987, 16. (From NewspaperSG)
8.  “Threat Posed By 'Unholy Trinity' Very Real — Raja,” Straits Times, 27 June 1987, 14. (From NewspaperSG)
9.  Alan John, “Govt Detains Six More,” Straits Times, 21 June 1987, 1. (From NewspaperSG)
10. “Four Catholic Priests Resign from Posts in Church Organisations,” Business Times, 5 June 1987, 1. (From NewspaperSG)
11. “What We Will Not Tolerate – PM,” Straits Times, 3 June 1987, 1. (From NewspaperSG)
12. “Archbishop Accepts Evidence,” Straits Times, 3 June 1987, 1. (From NewspaperSG)
13. “Four Catholic Priests resign from Posts in Church Organisations,” Business Times, 5 June 1987, 1. (From NewspaperSG)
14. “Vincent Cheng Interview on TV,” Straits Times, 8 June 1987, 1. (From NewspaperSG)
15. “Vision of Classless Society,” Straits Times, 10 June 1987, 14; “How Church Was Used as Cover for Subversion,” Straits Times, 29 May 1987, 16. (From NewspaperSG)
16. “Wah Piow Introduced Me to Mao’s Works – Cheng,” Straits Times, 10 June 1987, 14.
17. “How Church Was Used as Cover for Subversion.” 
18. “Wah Piow Letters Tell of Plans,” Straits Times, 28 May 1987, 1. (From NewspaperSG)
19. “12 Talk about Their roles in Marxist Plot,” Straits Times, 29 June 1987, 1. (From NewspaperSG)
20. “Nine Ex-Detainees Say They Had Been Ill Treated,” Business Times, 19 April 1988, 3. (From NewspaperSG)
21. Liak Teng Kiat, “Govt Explains Re-arrest of Eight,” Straits Times, 21 April 1988, 1. (From NewspaperSG)
22.  Liak, Govt Explains Re-arrest of Eight.”
23. John, “Govt Detains Six More.”
24. Ben Davidson, “High Court Dismisses Applications of Three,” Straits Times, 28 May 1988, 21. (From NewspaperSG)
25. David Gabriel, “The Start of a New Chapter,” Business Times, 22 June 1990, 11. (From NewspaperSG)
26. “Cheng’s Application Dismissed,” Straits Times, 1 February 1990, 2. (From NewspaperSG)
27. “ISD Detainee Teo Soh Lung Released on 3 Conditions,” Straits Times, 2 June 1990, 1. (From NewspaperSG)
28. Martin Soong, “Vincent Cheng Released from Detention,” Business Times, 20 June 1990, 28. (From NewspaperSG)
29. “Amended ISA Takes Effect,” Business Times, 31 January 1989, 1. (From NewspaperSG)
30. “Religious Harmony Act Effective on March 31,” Business Times, 28 March 1992, 2. (From NewspaperSG)
31. Fong Hoe Fang, That We May Dream Again (Singapore: Ethos Books, 2009), 106–32. (Call no. RSING 365.4509225957 THA)
32. Tessa Wong, “Two Ex-ISA Detainees Join SDP”, Straits Times, 20 February 2011, 4. (From NewspaperSG)
33. Danson Cheong, “Ex-detainees Launch Book to Mark 1987 Arrests, Call for ISA to Be Abolished,” Straits Times, 22 May 2017, 4. (From NewspaperSG)

Further resources

Tan Wah Piow, Smokescreens & Mirrors: Tracing the “Marxist Conspiracy,” (Singapore: Function 8 Limited, 2012). (Call no. 322.42095957 TAN)

Teo Soh Lung, Beyond the Blue Gate: Recollections of a Political Prisoner (Singapore: Function 8, 2011). (Call no. RSING 365.45092 TEO)

Teo Soh Lung and Low Yit Leng, eds., Escape from the Lion's Paw: Reflections of Singapore's Political Exiles (Singapore : Function 8, 2012). (Call no. 364.1322095957 ESC)

The information in this article is valid as of October 2023 and correct as far as we can ascertain from our sources. It is not intended to be an exhaustive or complete history of the subject. Please contact the Library for further reading materials on the topic.



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