If confirmed, it would be the fifth Covid-19 case linked to the Kowloon Tong eatery at the centre of an Omicron outbreak.
According to sources, the patient is the wife of a construction worker whose infection was confirmed earlier.
They sat at a table that was about 10 metres away from that of a Cathay Pacific crew member who’s believed to have spread the virus.
The woman has already been placed under quarantine.
Secretary for Food and Health Sophia Chan said on Sunday that some of the 200 or so diners at the Moon Palace restaurant on Monday afternoon have not been tracked down yet.