A top Hong Kong official has resigned after attending a birthday party with about 200 guests in early January as the city was battling a coronavirus surge.

Secretary of home affairs Caspar Tsui was among several officials ordered to quarantine after the party, which was held for Witman Hung, a delegate to China’s legislature.

At least one guest later tested positive.

Mr Tsui said he had not “set the best example during the recent outbreak”.

At the time, Hong Kong leader Carrie Lam and health officials had urged the public to avoid largegatherings to prevent the spread of the virus.

Mr Tsui said: “I made the wrong decision to attend a banquet on January 3 and behaved in an inappropriate manner when all efforts should have been devoted to controlling the spread of the virus.

“I will take responsibility for my actions, and I have therefore decided to resign from the position of secretary for home affairs.”

Mr Tsui’s announcement came hours ahead of a planned news conference by Ms Lam, who is widely expected to announce the results of a disciplinary investigation into officials who had attended the party.

Ms Lam expressed disappointment at the behaviour of the officials and legislators who attended, and ordered those in quarantine to be suspended from their duties.