The Executive Council has ordered the Registrar of Companies to strip the license of an alliance behind the June 4 vigil.
The order was made yesterday to revoke the license of the defunct Hong Kong Alliance in Support of Patriotic Democratic Movements of China.
"The Chief Executive in Council agreed with the views of the commissioner of police and the secretary for security that the operation of the alliance, which seeks to end the leadership of the [Communist Party of China], amounts to seeking to overthrow the basic system of the People's Republic of China established by the constitution with a view to subverting the state power of the PRC, which would inevitably threaten or undermine the PRC's ability to safeguard national security and to maintain public safety and public order," a government statement read.
A spokesman said there is a "practical need" to act quickly.
"Safeguarding national security is a matter of fundamental importance. Prohibition of the operation of the alliance is a necessary and proportionate restriction on the rights to freedom of association and freedom of speech or expression," the spokesman said.
Richard Tsoi Yiu-cheong, liquidator of the alliance, said because of the stripping the liquidation process could no longer continue. And the alliance has officially been banned instead of having disbanded.
Tsoi said the move was "unnecessary" after the alliance passed a resolution to go into liquidation last month.
Meanwhile, Chief Executive Carrie Lam Cheng Yuet-ngor yesterday said no one can prove that the national security law is the specific reason for associations and individuals exiting Hong Kong.
Her comments came a day after Amnesty International said it would close its two offices in Hong Kong by the end of the year, blaming the national security law imposed on June 30 last year.