Ma told RTHK that he and his wife are now considered close contacts and are being put in quarantine, after they had a meal with the infected woman at Happy Valley Racecourse last week.
The 43-year-old woman was one of the nearly 200 people who attended the birthday party of another NPC delegate, Witman Hung, on January 3.
Even though she wasn’t on Hung’s guest list, she joined the party along with a 37-year-old woman who is now a confirmed Covid patient.
The Jockey Club (HKJC), for its part, confirmed that the 43-year-old was at the race meeting at Happy Valley on January 5, and was in the same box with two other members.
It added that one of the two members was at Sha Tin Racecourse on Sunday and was asked to leave immediately.
The HKJC said it has told staff who served in the affected venues to stay home and get tested for Covid as soon as possible.
The club also said that in light of the “deteriorating external pandemic situation,” it will seek government approval to turn several upcoming races into closed-door events.
According to the latest compulsory testing notice, people who visited the parade ring and member voting boxes at Happy Valley Racecourse between 5pm and 10pm last Wednesday will need to undergo four tests in the next two weeks.