At least one guests later tested positive, and Secretary of Home Affairs Caspar Tsui was among several officials and lawmakers ordered to quarantine after the party, which was held for Witman Hung, a delegate to China's legislature.

Tsui said in a statement issued Monday afternoon that 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 large gatherings to prevent the spread of the virus.

``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,'' Tsui said.

``I will take responsibility for my actions, and I have therefore decided to resign from the position of Secretary for Home Affairs.''

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

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