The Prime Minister is facing questions over her former interim chief of staff who, according to records, never officially stepped aside from his role at a lobbying firm at the time.

A spokesperson for the Prime Minister said on Friday the former interim chief of staff had signed two codes of conduct when he took on the role, and that he filled out a conflict of interest form.

But there is no official declaration in the New Zealand Companies Office records - a government agency - that shows Thompson stepped aside from the company he was a director at, during that time.

GJ Thompson spent five months as interim chief of staff to Prime Minister Jacinda Ardern between October 2017 and February 2018, assisting the new Government transition into the Beehive.

The Thompson Lewis lobbyist has claimed he didn't do any work for the firm - of which he was a part-owner - while working at the Beehive, and said he wasn't paid either.

Ardern - who knew Thompson from her days working in former Prime Minister Helen Clark's office - has insisted Thompson stepped aside from the lobbying firm during the months he served as her interim chief of staff.

Her spokesperson said conflicts of interest are a matter for Ministerial Services (MS), and that as per an agreement with MS, Thompson took a leave of absence from his day-to-day duties at Thompson Lewis while he was interim chief of staff.

The spokesperson said they were advised that the arrangements agreed between MS and Thompson reflected the short term nature of the appointment.

Thompson did not respond to Newshub's request for comment on Friday.