The head of the Australian Federal Police has rejected suggestions he has a conflict of interest due to his relationship with a senior figure at embattled consulting firm PwC.

Commissioner Reece Kershaw has faced questions about his messages and meetings with former NSW Police commissioner Mick Fuller, now a partner at the consulting giant.

The AFP has been investigating the alleged leaking of confidential Commonwealth tax information by PwC’s former head of international tax, Peter Collins.

Mr Kershaw told Senate estimates in May he was contacted by Mr Fuller over the PwC tax scandal.

But in his opening statement to a spill-over hearing on Friday, Mr Kershaw said he and Mr Fuller had a “collegial relationship” that did not constitute a social friendship.

“Mr Fuller and I do not have dinner at each other’s homes, we do not play golf together and I don’t know the personal details of his life,” he said.

“The majority of the conversations Mr Fuller and I have had are about matters relating to our former or current roles or policing issues in general.

“What we have in common is dedication to service to the community and keeping our people safe.”

Mr Kershaw said he was not involved in the procurement process for a $794,000 contract to review ACT policing, which was awarded without a public tender to PwC for a project led by Mr Fuller.

The AFP commissioner said Mr Fuller was selected because he was the best person for the job.

“The contract Mr Fuller undertook was a job for a former police commissioner who had the required knowledge and expertise for a review,” he said.

“It was critical the reviewer had a contemporary skill set and knowledge of the unique operating environment of the ACT.”

AFP chief operating officer Charlotte Tressler was involved in the procurement process for the AFP review contract and previously worked in various roles at PwC, including as a director.

She did not previously disclose her employment history at PwC, a stint that ended in 2009, to the committee.

But Ms Tressler said the information was openly listed on her LinkedIn profile and she had declared any potential conflict of interest in all the procurement process she had been involved in.

“I have in no way attempted to hide my previous employment relationship with PwC,” she said.

Greens senator David Shoebridge questioned the commissioner about a meeting he had with Mr Fuller before a separate meeting about the contract for the review.

Mr Kershaw said there was a record of the pre-meeting taking place but no record of what was discussed.

He could not recall if the pair had discussed the proposed contract between PwC and the AFP.

Senator Shoebridge also pointed to repeated text messages between the pair, obtained under a Freedom of Information request.

Mr Kershaw said those messages did not reflect a social relationship with Mr Fuller but rather their unique experiences as police commissioners.

“There’s a lot of ex-commissioners going way back that still contact me … and it’s often just about general things,” he said.

“It’s a job that no one understands until you’ve done it … it’s not what you’re characterising as these deep friendships and relationships.

“Commissioners, when they retire or leave, they have to carry a lot of secrets with them … and sometimes people want to help each other out and support each other.”

– AAP