The police letter said the request was made because it was “reasonable to believe” it would help investigate possible crimes against national security. The alliance must provide the information within 14 days, or they could be prosecuted, it added.
Hong Kong police confirmed to CNN in a statement that they had requested “certain persons” provide information that is “related to the maintenance of national security,” but declined to provide more details.
The letter came after public broadcaster RTHK reported this week that the alliance has considered disbanding following Beijing’s promulgation last year of a sweeping national security law that criminalizes secession, subversion, terrorism and collusion with foreign forces.
The Hong Kong Alliance has held the annual candlelight vigil on the anniversary of the crackdown since 1990.
The events of Tiananmen Square began with protesters in Beijing, mostly college students, gathering in the heart of the Chinese capital to mourn the death of an ousted former leader — then, to push for governmental reform and greater democracy. In the early hours of June 4, the Chinese military entered the square, with orders to put down the protests.
No official death toll has ever been released, but rights groups estimate hundreds, if not thousands were killed. The protests and crackdown have been wiped from the history books in China, censored and controlled. The annual candlelight vigil in Hong Kong has been, for decades, the only mass memorial held on Chinese soil.