Police also ordered the group to take down its website and social media platforms and authorities also vowed to revoke its registration as a company
The Hong Kong pro-democracy group that organised three decades of annual vigils commemorating the victims of Beijing's Tiananmen Square crackdown voted to disband on Saturday in the face of China's sweeping clampdown on dissent in the city.
The Hong Kong Alliance was one of the most prominent symbols of the city's former political plurality and its dissolution is the latest illustration of how quickly China is remoulding the business hub in its own authoritarian image.
"This is a very painful dissolution," Tsang Kin-shing, a member of the alliance, said after the group's leadership voted to dissolve after 32 years.
"The government uses all kinds of laws to force civil society groups to disband," he added.
Many of the alliance's leaders are already in jail for taking part in the city's democracy movement. Earlier this month, police charged three senior figures with subversion -- a national security crime.
That same week, officers raided a shuttered museum the group ran commemorating Beijing's deadly 1989 Tiananmen Square crackdown, hauling away exhibits, memorabilia and photographs of the historic event.
Police also ordered the group to take down its website and social media platforms and authorities also vowed to revoke its registration as a company.
In a letter from prison, one of the alliance's leaders, Chow Hang-tung, urged members not to give up.
"I still hope to show Hong Kong Alliance's beliefs to the world and continue this movement that has already lasted for 32 years," Chow said in a letter that was uploaded to her Facebook page.
But two other jailed leaders -- Lee Cheuk-yan and Albert Ho -- had signed letters calling for the group to disband, citing "the current social environment".
Huge and often violent democracy protests engulfed Hong Kong in 2019. China responded with a sweeping crackdown, including imposing a new national security law that has criminalised much dissent and been used to purge any person or political group deemed to be disloyal.
More than 90 people have been charged under the law, while dozens of civil society groups -- including unions and political parties -- have dissolved.
Beijing's top official in the city recently said those who cry for "ending the one-party dictatorship" are "real enemies".
The alliance was told it was under investigation by the national security unit earlier this year and was ordered to hand over a host of documents and details on its membership.
Unlike many opposition groups which quickly folded or obeyed police requests, the alliance took a more defiant approach.
Many of its leading figures are lawyers and they argued the police request was illegal.
Once the alliance confirmed it was not going to cooperate with the investigation, police brought subversion charges against its leaders.
Officially titled the Hong Kong Alliance in Support of Patriotic Democratic Movements of China, the group was founded in May 1989 to support students holding democracy and anti-corruption rallies in Beijing.
A month later, China's leaders sent tanks and soldiers to crush the movement in Tiananmen Square, a decision it has since heavily censored and removed from public record on the mainland.
Over the following decades, the alliance kept the memories of Tiananmen alive and called for China's communist leaders to embrace reforms with slogans like "End one-party rule" and "Build a democratic China".
Each June 4, the group organised candlelight vigils in Hong Kong's Victoria Park that were routinely attended by tens of thousands of residents, the crowds swelling in recent years as anger over how Beijing was running the city intensified.
That anger exploded in seven months of democracy protests in 2019, which Beijing clamped down on.
But the last two Tiananmen vigils were banned, with authorities citing the coronavirus pandemic and security fears.