Hong Kong's Legislative Council President Andrew Leung Kwan-yuen said on Friday four lawmakers were taken to the Penny's Bay Quarantine Centre after attending a private banquet with a guest who was preliminarily tested positive for COVID-19 on Monday.

The four lawmakers - Rock Chen Chung-nin, Duncan Chiu Tat-kun, Benson Luk Hon-man and Wendy Hong Wen were among the 19 lawmakers who attended the banquet.

Over a hundred people joined the birthday banquet held in Wan Chai for Witman Hung Wai-man, principal liaison officer for Hong Kong at the authority managing the Shenzhen's Qianhai free trade zone, with at least 10 government officials attending as well. Hung and Secretary for Home Affairs Caspar Tsui Ying-wai were later sent to the quarantine center for attending the event.

Junius Ho Kwan-yiu, who also attended the party, was also among over a dozen lawmakers who met with Xia Baolong, vice-chairman of the National Committee of the Chinese People's Political Consultative Conference and director of the Hong Kong and Macao Affairs Office of the State Council, in Shenzhen on Wednesday.

Leung said Ho tested negative three times before meeting Xia.

Stressing lawmakers should be accountable to the public, Leung said all involved lawmakers and their assistants are required to be tested and will not return to their office without negative test results.

Leung said the council's first assembly scheduled next Wednesday will be held as planned, until the situation proves otherwise. Chief Executive Carrie Lam Cheng Yuet-ngor will also attend the assembly and hold a question and answer session to respond to concerns of the lawmakers.