Sources said on Wednesday that Hong Kong national security police have arrested four people, including 90-year-old Cardinal Joseph Zen and singer Denise Ho, in connection with a now-defunct fund that raised money for the legal and medical fees of anti-government protesters.

The others detained are understood to be former lawmaker and barrister Margaret Ng, and cultural studies scholar Hui Po-keung.

Ho's assistant confirmed with RTHK that the singer was taken from her home on Wednesday evening.

The 612 Humanitarian Relief Fund was set up in June 2019 to provide financial aid to those who were hurt or arrested during the social unrest. It paid for legal assistance and funded medical treatment, psychological counselling and emergency relief.

The fund ceased operations last year, soon after national security police revealed they were investigating it, and requested information on its operations and financial transactions.

The four, who were former trustees of the fund, are said to have been arrested on suspicion of conspiring to collude with foreign forces to endanger national security.

It's understood they were taken separately to police stations in Wan Chai, Western, Chai Wan and Kwai Chung.

All four were later released on bail pending further investigations.

The Vatican had said on Wednesday it was concerned over the reports that Cardinal Joseph Zen had been arrested.

"The Holy See has learnt the news of Cardinal Zen's arrest with concern and is following the development of the situation very closely", the Vatican said in a brief statement.

The 612 fund had five trustees in total. The remaining one is jailed democracy activist Cyd Ho. She is serving a 14-month jail sentence for involvement in different illegal assemblies in 2019.

Last updated: 2022-05-12 HKT 01:12