An inquiry into complaints about public service commissioner John Lloyd's conduct remains unfinished less than a week before his retirement will put him beyond investigation.
The federal government official responding to claims of misconduct involving Mr Lloyd, merit protection commissioner Linda Waugh, has confirmed the probe is yet to finish.
She declined to comment but said she intended to conclude the inquiry as quickly as possible.
Under public service legislation there is no power to investigate Mr Lloyd once he departs the Australian Public Service Commission on August 8. The commission on Thursday also declined to comment.
Acting merit protection commissioner Bruce Barbour, filling in for Ms Waugh as she took pre-arranged leave, decided to launch an investigation into a second complaint about Mr Lloyd in July.
In an email sent in June, the complainant alleged Mr Lloyd breached a code of conduct by using his public service commission email address in October when writing to the head of a right-wing think tank following questioning by senators about his links to the group.
Former Commonwealth ombudsman, acting NSW ombudsman and Australian information commissioner John McMillan was asked to conduct an inquiry into a complaint lodged in December about Mr Lloyd.
The allegation raised in the first complaint has not been described publicly.
Mr Lloyd, whose term was due to expire in December 2019, abruptly announced in June he would resign but denied the timing was influenced by a possible investigation.
His agency said then he had "for some time" considered departing before his term as commissioner ended, and Mr Lloyd later told senators he had felt it was time to resign after a long career.
The commissioner's announcement came after mounting pressure over his connection to the Institute of Public Affairs, and revelations in May he faced a possible inquiry.
Mr Lloyd's links to the think tank came under growing scrutiny after it was revealed at a Senate estimates hearing in October he sent an email to a member of the IPA with an attachment showing what he described as "generous" provisions in public service enterprise agreements.
He has rejected suggestions he gave it special access and research.