HONG KONG - Chief Executive Carrie Lam has ordered a probe into 13 officials to see if they breached any rules for joining a birthday party of a delegate to the Chinese legislature - in a widening scandal that has not only hampered anti-epidemic efforts but also angered people.

Food and Health Secretary Sophia Chan on Saturday (Jan 8) said the number of guests at the party exceeded 180, up from the previously reported 170.

"Colleagues from the Department of Health have been issuing quarantine orders. At present, there should be 80 people already who have entered the quarantine centre at Penny's Bay," she told a local radio programme.

Professor Chan said the government will consider ordering close contacts of confirmed cases to serve home quarantine instead of at quarantine camps if the facilities fill up.

The guests, including two ministers - Home Affairs Secretary Caspar Tsui and Secretary for Financial Services and Treasury Christopher Hui - and 19 lawmakers of the newly formed Legislative Council, had on Monday attended the 53rd birthday celebration of Prof Witman Hung, the Hong Kong Deputy to the 13th National People’s Congress.

All 19 lawmakers and the two ministers have tested negative for Covid-19. 

The ministers were sent to Penny's Bay camp after an infected guest attended the party and a second guest later tested preliminary positive for the virus. 

But on Saturday, the health authorities said further tests showed that the second guest, a presenter from broadcaster RTHK, was not infected. 

Microbiologist and government adviser Yuen Kwok Yung said the presenter's test was believed to be contaminated after the doctor who took her sample - the presenter's husband, with his private clinic - vaccinated 13 people before the testing. 

He said the virus strain in the specimen taken from the presenter is the same as the one used to make the Sinovac vaccine and different from the strains circulating in the community. 

The one positive case at the party had arrived at about 9.30pm after the presenter. Guests who arrived after 9.30pm will be quarantined, while the quarantine order will be lifted for those who got to the party earlier.

The false alarm abruptly ended the quarantine of several officials after a day-long stay.

In a statement issued early on Saturday, Mrs Lam said she has instructed the director of the Chief Executive's Office Chan Kwok Ki and Civil Service Secretary Patrick Nip to make "detailed investigations" into whether the attendance of the 13 officials "constitutes any breach of discipline".

"The investigation will cover the detailed circumstances of the attendance of each official at the banquet, including the time of arrival, duration of stay and their behaviours there," she said.

Mrs Lam added that the investigation and enforcement action by the health authorities will cover aspects such as whether an attendee used the LeaveHomeSafe app and wore a mask.

She also relieved the duties of all 13 officials in quarantine, saying that "they should not continue to discharge their duties and that they are required to take their own vacation leave for quarantine". The duties will be covered by other colleagues concurrently.

Photos of guests unmasked and masked have gone viral, drawing anger and flak from people, some of whom demanded accountability on social media as they said these officials and lawmakers have directly contributed to the fifth wave of pandemic in Hong Kong.

The party took place a few days after Prof Chan on Dec 31 warned against large gatherings in view of the unstable Covid-19 situation, before new restrictions on social life came into force and after Mrs Lam urged residents not to have large gatherings.

On Saturday, Prof Chan said Hong Kong is at a "critical moment" where "the epidemic situation has reversed, and our community already has multiple chains of transmission".

She said manpower has been beefed up to help with contact tracing and urged people to adhere to testing notices.

Apologies continued to stream in on Saturday, with the two ministers and at least five senior officials, including Under Secretary for Constitutional and Mainland Affairs Clement Woo and Commissioner of Police Raymond Siu, doing so.

In an attempt to contain the pandemic, the government on Friday banned dining at food establishments after 6pm and closed 15 types of venues such as bars, gyms, cinemas and beauty salons for two weeks. Gatherings are capped at four people.

The health authorities on Saturday said Hong Kong added 37 cases, of which six were imported and one case was untraceable. 

There were another 30 people who tested preliminary positive. This brought the total to more than 12,700 confirmed cases and 213 deaths.

The authorities said they will order all those who went to singer Hins Cheung concert on Jan 3 to get tested after a woman who attended the event with her husband tested preliminary positive.

The tripling of imported cases in the past month has worried the authorities.

Some of the transmission chains were sparked by two Cathay Pacific crew members who returned from the United States, one of whom broke company quarantine rules and went out. The other had passed the Omicron variant to her mother, who is linked to clusters at Victoria Park and a Tin Hau eatery.