The face of the Queensland Government's move to expunge convictions related to homosexuality may be unable to clear his name under the new laws.

Alan Raabe, 64, stood by Premier Annastascia Palaszczuk and Attorney-General Yvette D'Ath in May last year when they made an apology to people convicted of being homosexual.

But the laws that passed Parliament only allowed for public morality offences and male homosexual offences to be expunged, and do not include the other offences that people were charged with.

Mr Raabe said he was walking along the beachfront esplanade in Cairns in 1988 when he was targeted by an undercover police officer.

"It was very late at night," Mr Raabe said.

"I was walking along The Esplanade and a very handsome young man walked towards me and gave me what I thought was 'the eye'.

"I followed him and we ended up in a very dark corner of the park, totally isolated and surrounded by trees and bushes.

"I approached him cautiously and then eventually brushed up against him and made a suggestion that we get together.

"And he said, 'That's a pity, because I'm a policeman.'"

Mr Raabe was arrested and charged with sexual assault and pleaded guilty to the charge in court.

He maintains he only approached the man because he was made to believe it was consensual.

LGBTI Legal Service lawyer Emil McPhee is acting for Mr Raabe and said police posing as gay men appeared to be a common method of charging for homosexual offences at the time.

"The [story] of busting into a room and finding two men in bed doesn't seem to have happened too often," he said.

"There are some limited examples of those.

"But it seems like the ones that happened frequently and the ones we had hoped these laws would cover are these offences where somebody was, for lack of a better word, entrapped."

Most people won't be able to clear their names, lawyer says

Mr McPhee said the laws as they stood would prevent most people charged with homosexual-related offences from clearing their name, because offences that still existed, such as assault, could not be expunged.

"It was quite unfortunate really that [Alan] spent so long being the poster boy, only to find out quite late in the piece that his wouldn't be eligible."

Mr McPhee said that around 500 people would be eligible with a broad test applied, but as things stand, the numbers are unclear.

"It might be only a handful of people, which would be a real problem," he said.

The Northern Territory Government introduced similar laws this year.

New South Wales, Western Australia, the ACT and Victoria already have more broad laws in place, while South Australia allows for convictions to be "spent" but not expunged.

To have a conviction expunged means a person can legally say they were never convicted.

A spokeswoman for Queensland Attorney-General Yvette D'ath said the Queensland legislation, which came into effect on June 30, does allow for modification.

"The Attorney-General specifically drafted the legislation so that there is room to add further offences if pertinent examples come to light.

"It should be noted it is very early days and the Director-General is yet to rule on any applications for expungement," she said in a statement.

"The apology and the legislation were important steps to acknowledge the harm that had been inflicted on people when homosexual activity was considered a criminal offence."