The late Szeto Wah had a high regard for Britain's MI6 intelligence agency, which helped rescue students in Shanghai in the aftermath of the 1989 crackdown.
In his memoirs, Szeto also disclosed that he sacked one of those involved in Operation Yellowbird for allegedly disclosing the group's escape routes to mainland authorities after the man's brother was arrested.
The late chairman of the Hong Kong Alliance in Support of Patriotic Democratic Movements of China said in his memoirs that he arranged for three students to meet MI6 agents after he asked the British government to rescue them on humanitarian grounds.
At the meeting, one of the students took out a lighter and told agents he had used it to burn cars in a student campaign in Shanghai.
Szeto said he was surprised when the agents then played a video which showed the trio in action. The three were rescued.
"[Szeto Wah] praised the British secret service as an extraordinary group who did an excellent job in collecting intelligence," his sister Szeto Sim said.
With extensive assistance from the colonial government, the Hong Kong-funded Operation Yellowbird, which began in late June 1989 after Beijing announced its wanted list, successfully helped more than 400 dissidents to escape from the mainland.
The alliance spent HK$500,000 to HK$600,000 to rescue each movement leader and covered all their expenses, including their arrival costs, airfare and initial expenses abroad.
Szeto also alleged that the "highly confidential" operation was exposed by Chan Tat-ching, a frontline commander.
He said only six alliance members knew about the secret operation and it was never mentioned in the group's official meetings.
According to Szeto's memoirs, Chan allegedly disclosed to the Communist Party escape routes after his brother was arrested by mainland police. At the time, Chan was a wine trader with connections ranging from senior mainland officials to smugglers.
Szeto stressed that Chan had "never been the operation's mastermind," but a boatman or snake-head instead. An angry Szeto expelled him from the rescue group.