Civil Service chief Ingrid Yeung on Saturday said investigations under the two-tier accountability system will continue when a department head retires.

Under the rule unveiled in the latest Policy Address, any problem identified will be handled by heads of department or an independent panel, based on the severity.

She told RTHK that a department head who has resigned will still be investigated.

"If the staff member has retired or quit... the investigation still needs to continue because very few incidents involve only one person. Some documentation records and files still exist, and a lot can be discovered from them. The investigation must proceed," she said.

"If the personnel concerned have already left or changed positions, reports still need to be addressed and everything has to be disclosed," she said.

Yeung said if a staff member intentionally tries to avoid disciplinary proceedings following an investigation, the government will still be able to act.

For instance, if the worker opts for early retirement by making use of remaining vacation leave, the government will not hand out the pension immediately, she added.