A combination of alcohol and a prescription drug have been revealed as the reason behind a February 7 video of Barnaby Joyce swearing into his phone while lying on a Canberra street.
The former deputy prime minister told morning television he had "made a big mistake".
"There's no excuse for it, there's a reason," he told Sunrise on February 12.
"It was a very eventful walk home, wasn't it?
"I'm on a prescription drug and they say certain things may happen to you if you drink and they were absolutely 100 per cent right."
Nationals leader David Littleproud said he had spoken to Mr Joyce on the weekend to make sure he was okay.
"He's acknowledged this isn't normal behaviour and there's some personal circumstances, some of which he has articulated publicly, others that I don't intend to breach his confidence," he told Sky News on February 12.
"He's an important part of our team and we'll make sure that he gets the support that is required to ensure that he can continue to contribute."
Labor Senator Katy Gallagher was also asked about the incident on February 12 and said it was "incredibly sad".
"I hope he gets the help he needs because it's a very unusual position, I think, for someone of that age to be in," she told ABC Canberra.
"These things do nothing for the profession of politicians... it confirms in the public's minds negative association with politics and I think that's a real shame."
On the weekend a chalk outline and plaque were added to the scene on Braddon's Lonsdale St, where the Nationals frontbencher was filmed lying on the footpath while talking on the phone.
The plaque commemorates Mr Joyce "being totally f--- a--- drunk that time. 8th Jan 2024".
Mr Joyce said in a statement he was swearing at himself for having fallen over, after the Daily Mail reported he was heard mumbling "dead f---ing c--t" into the phone.
Mr Joyce said he had been sitting on the planter box on the way back to his accommodation when he fell off.
On the weekend Prime Minister Anthony Albanese told reporters in Ballarat an explanation was required and a "response of the Liberal and National Party leaders".
"I think people will also think to themselves, what would the response be if that was a minister in my government being seen to be behaving in that way?"
Opposition Leader Peter Dutton said he would "have a chat" with Mr Joyce in the coming week.
"It's pretty rough when people are walking past somebody who might need support," he told Sky News of the video.
"I understand a chalk mark has been drawn on the footpath. It could only happen in Canberra where all those Greens and Labor staffers are."