"Let there be no doubt that after caucus today I can confirm no NZ First Minister or MP sent any photos to any website," he tweeted before Question Time this afternoon.
Soon after the tweet, Ardern faced a barrage of questions from the Opposition in the House over the saga.
Ardern was again forced to confirm she did trust Peters and he had acted lawfully and behaved "in a way that upholds, and is seen to uphold, the highest ethical standards" as set out by the Cabinet Manual.
She faced similar questions by reporters in her weekly post-cab press conference yesterday.
Peters' tweet came soon after NZ First's weekly caucus meeting, where the photos would have been a hot topic.
This morning, Peters would not answer media questions about the photos.
Instead, he directed reporters to an interview he did with Magic Talk earlier that day.
"I don't know anything about it, and I'm not responsible for it," he said of the photos.
This time last week, Peters said "we" took the photos in a bid to show the "sort behaviour" that was going on.
He later walked that back, to say it was a supporter who took them and denied NZ First had hired a private investigator.
Speaking to Magic Talk again today, Peters said he had "no idea" how the photos and the videos ended up on the blog.
"I'm a busy man, I'm flat out – I'm not wasting my time with this. I have no idea who did what or when."
But senior NZ First MP and Minister Tracey Martin told media this morning she did know who took the photos - but wouldn't say who.
"It's not for me to say."
National deputy leader Paula Bennett said that was not good enough.
She said New Zealand First knows what has happened and knows who took the photos.
"Quite frankly, a tweet we have seen is not actually answering very important questions."