The Hong Kong Alliance in Support of Patriotic Democratic Movements of China did not submit the information police is seeking, such as details of its membership and operations. Four standing committee members of the alliance left the Wan Chai police headquarters after a 30-minute stay.

The alliance only formally replied to the police's national security department, which has accused them of being a "foreign agent."

"For anyone who does not hand over information in accordance with the law, police will carry out follow-up legal actions quickly," said Tang.

The alliance's vice-chairwoman, Tonyee Chow Hang-tung, said the standing committee members are mentally prepared to face the legal consequences.

One member, Tsui Hon-kwong, applied for a judicial review, asking the High Court to rule that the Commissioner of Police Raymond Siu Chak-yee's decision to give them the letter was wrong.

"It does not sit well with me that I have been a committee member of the alliance for 31 years and I love the country, but they said I am a foreign agent," Tsui said.

Without revealing names, the police force said they strongly condemn a group for stating that they will not abide by the request.

Police warned that members of the group could be jailed for six months and fined HK$100,000 if they fail to submit the information on time.

Chief Executive Carrie Lam Cheng Yuet-ngor condemned the alliance's decision, saying: "If anyone publicly and openly states that they would not act in accordance with the law, I do not think they should be called a civil society organization."