They were among four people who were arrested for using the fake app “Back Home Safe” when they entered Immigration Tower in Wan Chai on Monday – the first day when all visitors to government buildings and premises like public wet markets and hospitals are required to use the LeaveHomeSafe app.

A fifth person was arrested after he showed a screen cap of his previous use of LeaveHomeSafe, instead of using the app on the spot.

In a briefing on Tuesday, police said the five were four men and a woman, aged between 22 and 45. Among them were a 34-year-old immigration officer, a 28-year-old immigration assistant and a 45-year-old examiner from the Audit Commission.

The other two government contractors were a man and a woman, aged 28 and 22 respectively.

Both the Audit Commission and the Immigration Department said that they highly value staff's integrity and no unlawful act or misconduct will be tolerated. They added that the matter will be handled seriously in accordance with the law and established procedures.

Police warned citizens that the installation of a fake LeaveHomeSafe app and an intention to use it can also be viewed as breaching the law, and condemned online remarks that encouraged people to use the fake app.

According to sources, developers of the fake LeaveHomeSafe app have received a letter from software development platform GitLab, which requested them to shelve the fake app in accordance to police order.

It was understood that police in the letter accused the fake app of forgery under the Crime Ordinance.

The fake app cannot be found on GitLab now. Yet the public can still access the app in web page format on other sites.