He says the informal briefing occurred in the back of a car as the pair travelled through the South Island.
Hipkins told Q+A that he had no recollection of the alleged conversation.
Coster also claimed he’d told current Minister of Police Mark Mitchell earlier than the November 2024 date that Mitchell has previously suggested.
“There is no way that I was only just telling him about all of this in my last couple of weeks in the job,” said Coster.
Coster resigned this week from his role as the chief executive of the Social Investment Agency.
It followed a damning Independent Police Conduct Authority (IPCA) report into the way police handled complaints against McSkimming, published in November. Coster had been on leave since the report was published.
Former Deputy Commissioner Jevon McSkimming. Photo / RNZ, Mark Papalii
Coster said his decision to resign was a result of his “acceptance of full responsibility for the shortcomings identified in the Independent Police Conduct Authority’s review of the handling of complaints against Jevon McSkimming during my tenure as Commissioner of Police”.
“I regret the impact on the young woman at the centre of this matter and sincerely apologise to her for the distress caused.”
The allegations were made by a woman, with whom McSkimming had an affair, over a number of years.
The woman, dubbed Ms Z because of suppression orders, spoke exclusively to the Herald about the “ongoing nightmare” she had suffered at the hands of the former Deputy Police Commissioner.
She had sent hundreds of anonymous emails over years, alleging McSkimming was a sexual predator who had groomed her.
While McSkimming had admitted a consensual affair with the much younger woman – she was 21 at the time, he was 42 – he denied the allegations and claimed she was motivated by revenge.
Senior police did not investigate the allegations, which continued as McSkimming sought the role of Police Commissioner, the most senior role within the police. The IPCA report noted the former police executive prioritised McSkimming’s ambitions in the force above investigating the complaints.
For years, that narrative was accepted by McSkimming’s supervisors, who instead used the emails as evidence to prosecute Ms Z amid McSkimming’s intention to replace outgoing Police Commissioner Andrew Coster.
McSkimming resigned in May after the discovery of objectionable images on his police devices, including child exploitation and bestiality material.
He pleaded guilty to charges related to that material and awaits sentencing.