A senior Catholic cleric in Hong Kong has been arrested, accused of breaking China's national security law and of colluding with foreign forces. 

Cardinal Joseph Zen (90) is one of four people who were detained on Tuesday (10 May) due to their links with the now disbanded 612 Humanitarian Relief Fund, which helped pro-democracy protesters pay their legal and medical fees.

Ex-legislator and veteran barrister Margaret Ng, academic Dr Hui Po-keung, and Canto-pop singer and actor Denise Ho are also being held. If found guilty, they could face life in prison.

‘Shocking new low’

Human Rights Watch called it a "shocking new low for Hong Kong."

"Arresting a 90-year-old cardinal for his peaceful activities has to be a shocking new low for Hong Kong, illustrating the city's free-fall in human rights in the past two years," the organisation said.

Cardinal Zen fled Shanghai for Hong Kong 70 years ago after the communist takeover in China. He is a former bishop of Hong Kong, where he was an outspoken critic of Beijing, is a strong defender of Catholics on mainland China, and continues to call for greater democracy in Hong Kong.

He once publicly criticised the Vatican for acquiescing with China in forcing bishops to retire in favour of Beijing-chosen replacements. 

Vatican concerned

The Vatican has said that it is concerned about the cardinal's arrest, saying that it was “following the development of the situation with extreme attention”. 

The Catholic Diocese of Hong Kong added that it was "extremely concerned about the condition and safety of Cardinal Joseph Zen. We urge the Hong Kong Police and the judicial authorities to handle Cardinal Zen's case in accordance with justice," it said.

Latest reports confirm that Cardinal Zen was released on bail from Chai Wan Police Station on Wednesday night, accompanied by five people. 

Other arrests of prominent figures

Hong Kong Free Press, citing two sources, said that scholar Dr Hui, who is associated with Hong Kong's Lingnan University, was arrested at the city’s airport before boarding a flight to Europe to take up an academic posting. He has now been released on bail.

Margaret Ng was handed a one-year suspended sentence in 2021 for taking part in unauthorised demonstrations. Hong Kong Free Press confirms that she was released after midnight on Thursday morning. “I’m a bit tired, but I’m still okay,” she told HKFP. 

Canadian singer and activist Denise Ho was detained late last year under the same law, and has been arrested twice during the past two months by Hong Kong’s National Security Police. Local media reports that Ho has also been released on bail.