Speaking on the eve of the crackdown's 30th anniversary, Lee Cheuk-yan said the Chinese public was "very much encouraged" by the Australian prime minister's announcement, which had a ripple effect among western countries.

"Everyone remembers Bob Hawke crying, weeping during the '89 demonstration and massacre," he said.

"Then the world condemned China.

"A lot of people that were rescued from China into Hong Kong were allowed to have political asylum in France, in Australia, in Europe and the United States."

Hundreds, possibly thousands, of pro-democracy protesters died when government troops opened fire in the square on June 4, 1989.

But Mr Lee, now an operator of the June 4 museum in Hong Kong, said world sympathy faded with China's emergence as an economic force.

"(Other countries) are talking about trade and then, on the side, you may have a human rights dialogue for the sake of looking good," he said.

"China want to buy you off and therefore you don't fight for human rights."

Though Mr Lee says mainland China is working to suppress June 4 commemorations, thousands are expected to mark the anniversary at a candlelight vigil in Hong Kong on Tuesday.

Remembering his own role in the protest, he said he was in working as a pro-democratic activist and organiser when he went to Beijing on May 30, 1989.

"When June fourth came I was told by the workers at the tent that I have to go back to my hotel because they are not going to block the army," he said.

"I heard the gunshot and then the massacre, the tanks rolling in and, on the street, you could see rickshaw drivers driving the injured people.

"We had hope for democracy and we were crushed by the massacre."

Hawke's announcement six days later to allow 27,000 Chinese students stay in Australia was remembered as a legacy of his prime ministership after his death last month.

Australian Associated Press