Hong Kong's Labour Department leaked use login names and passwords while upgrading its interactive employment service website on Nov1, the department said Thursday.

According to the department in a statement, user names and passwords of 220 users were sent to unauthorised individuals from 2pm to 2:55pm last Monday. Of these users, 51 user accounts were found to have been logged into from 2pm to 3:30pm.

"Upon detection of the irregularities, we took immediate remedial action and reset the passwords of all affected users by 3.30pm on the same day," said a spokesperson for the department. "No changes were made to data pertaining to those 51 accounts."

The department added that it has informed all affected users by email and assigned staffers to follow up with the 51 users whose accounts had been logged into. As of Nov 4, the department contacted 40 of those users and 31 of them confirmed the log-ins were made by themselves, the Labour Department noted.