The mysterious death of Inspector John MacLennan in 1980 sparked the most expensive public inquiry in Hong Kong's history, costing HK$16 million.
Before the 29-year-old Scot was found with five gunshots to the chest, he knew he was about to be interviewed by the Special Investigations Unit - a specialist police unit charged with investigating homosexuals.
MacLennan's death awoke the public and the authorities to the need to overhaul the law, and the government immediately appointed the Law Reform Commission to recommend whether the law needed to be changed.
Homosexuality was eventually decriminalised in 1991. But 22 years on, the city still does not have an anti-discrimination law protecting sexual minorities.
Discrimination is illegal under the Bill of Rights, but its provisions can be used only against the government and public authorities.
Michael Vidler, a legal adviser to Pink Alliance - a coalition of lesbian, gay, bisexual and transgender groups - said the basic values enshrined in the constitution mean that everyone is equal in theory, but that reality often doesn't measure up.
"In gay people's lives today, what in reality has changed?" he asked. "Many young people are still worried about coming out as gay at their place of work because they fear it will affect their employment. Even today, they still feel they have to lead a kind of double life."
Elsie Tu, an urban councillor in 1980, took a great interest in the MacLennan case and was in no doubt that the police officer had been caught up in a sinister plot.
"I don't believe for a moment that MacLennan committed suicide," she said.
"He was a good and honest man. What was said at the inquiry about him after his death were damn lies. It was an absolute disgrace."
In an interview with the Post on the eve of his retirement in 1994, Commissioner of Police Li Kwan-ha said the MacLennan inquiry had fallen short.
"The action at the scene could have been better handled," Li said. "There were a lot of doors that hadn't been closed, let alone locked, but there was no malice in anyone's actions."
Agnes Allcock's play Behind the Curtain is also not the only one to refer to MacLennan's suspicious death. In 1995, Michael Hurley's production of the 20th century classic Accidental Death of an Anarchist replaced references to the politics of post-war Italy with references to more contemporary examples of intrigue.
The most effective of these was a reference to the supposed suicide of MacLennan.