Officials say the genetic sequencing of the coronavirus found in a 27-year-old airport worker is identical to strains found in patients arriving from Indonesia.
The man’s infection was recorded on Thursday.
The Centre for Health Protection reported four new coronavirus cases on Friday, all of which involved overseas arrivals.
Two of the patients had flown in from the UK, while the others arrived from Indonesia and Bangladesh.
Meanwhile, authorities imposed a testing order for residents of a Yuen Long block, after a 19-year-old girl who lives there was confirmed with the coronavirus after she flew to London.
Anyone who had been to Tower 2 of Springdale Villas for more than two hours between May 31 and June 13 must take a Covid test.