With the exception of Vincent Cheng, all the detainees were released, on various dates, before the end of 1987. On 18 April 1988, nine of the ex-detainees released a joint statement to the press. In the statement, Teo Soh Lung, Kevin Desmond de Souza, Tang Lay Lee, Ng Bee Leng, William Yap Hon Ngian, Kenneth Tsang Chi Seng, Wong Souk Yee, Chng Suan Tze, and
Tang Fong Har said that even though they had hitherto kept a "fearful silence", they decided to release a statement because of "the constant barrage of Government taunts and its public invitation to speak the truth". The following are extracts from the statement: One day after release of the statement, all the signatories except Tang Fong Har, who was in the United Kingdom at the time, were re-arrested. Patrick Seong Kwok Kei, a
Law Society Council member and one of the lawyers who had acted for several of the detainees in 1987, was also arrested on the same day. On 6 May 1988, lawyer
Francis Seow, who was representing Teo Soh Lung and Patrick Seong Kwok Kei, was arrested under the Internal Security Act while waiting inside the Internal Security Department's headquarters to meet his clients. He was supposed to have filed for writs of
habeas corpus for his clients on the same day. The government accused him of "colluding with foreign diplomats and officials to lead a group of opposition lawyers and professionals into Parliament." He was alleged to have misused his status as a legal counsel as a cover for political propaganda and agitation. Seow was held in detention for 72 days and was released, subject to restrictions on his freedom of movement and association, as a result of pressure by international human rights organisations. He was later charged and convicted
in absentia for
tax evasion, having left Singapore to live in exile in the United States where he became a Fellow at the Department of Asian Studies at
Harvard University. During the 28th year of his exile, Seow died at the age of 87 in January 2016. In response to the ex-detainees' allegations of ill-treatment, the
Ministry of Home Affairs announced on 19 April that a Commission of Inquiry would be held to determine if the Marxist conspiracy was a government fabrication and whether the detainees were assaulted and tortured.
Trade and Industry Minister Lee Hsien Loong said that "the Government does not ill-treat detainees. It does however apply psychological pressure to detainees to get to the truth of the matter... the truth would not be known unless psychological pressure was used during interrogation."
Ow Chin Hock, Member of Parliament for
Leng Kee, revealed later that Singaporeans, notably intellectuals, had "harped on the need to protect detainees' rights". The ex-detainees who were arrested eventually signed statutory declarations (SDs) reaffirming their original statements to the Internal Security Department. Five of the detainees said that they were not ill-treated. Vincent Cheng was conditionally released after three years 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. Minister for Home Affairs
S. Jayakumar stated that there was no longer a need to hold a Commission of Inquiry as investigations had showed that the ex-detainees "were not... seeking judicial or legal redress but were acting as political propagandists out to discredit the Government." He also claimed that the foreign press had "hysterical" reactions to the news of the re-arrests, which "did not come as a surprise" to the government.
Habeas corpus See Changes to the law After the re-arrests, four of the detainees – Teo Soh Lung, Kenneth Tsang Chi Seng, Wong Souk Yee and Kevin Desmond de Souza – were issued with one-year detention orders. They engaged
Anthony Lester and
Geoffrey Robertson,
Queen's Counsels (QC) from the United Kingdom, to apply to the
High Court for writs of
habeas corpus, a legal action that requires a person under arrest to be brought before a judge to challenge detention lacking sufficient cause or evidence. They were unsuccessful. They then appealed to the
Court of Appeal. In a landmark ruling, 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 writs of
habeas corpus, but – with the exception of Teo – later withdrew their applications and were released. Teo's application was dismissed by the High Court after the government amended the
Constitution and the Internal Security Act to reverse the Court of Appeal's earlier decision. The amendments were expressed to operate retroactively. The legality of these amendments was unsuccessfully challenged by Teo in
Teo Soh Lung v. Minister for Home Affairs (1989–1990) and Vincent Cheng in
Cheng Vincent v. Minister for Home Affairs (1990). ==Impact of Operation Spectrum==