Prime Minister Anthony Albanese is facing questions over a private lunch in Victoria with one of Australia's richest men.
Mr Albanese was flown in Lindsay Fox's private helicopter for a meeting at his Portsea mansion on Saturday, which was also attended by Victorian Labor Premier Dan Andrews, Nine newspapers reported.
The meeting came after the prime minister finished a media conference in Geelong and before flying to Western Australia to inspect flood damage.
The newspapers reported Mr Albanese had lunch with the logistics industry leader and had a swim.
Mr Fox is understood to be seeking to develop his private Avalon airport into an intermodal transport hub, which would likely require Victorian and federal government assistance.
When asked about the meeting, Mr Albanese told reporters on Wednesday: "I have private meetings all the time. And I have private meetings which are private meetings."
Deputy opposition leader Sussan Ley told reporters on Thursday the prime minister should be upfront about what was discussed.
"Anthony Albanese has refused to disclose what he discussed - we don't know what special requests were made of the prime minister," she said.
"We do know he willingly accepted a private helicopter flight to a billionaire's mansion."
She also questioned why Mr Albanese needed to take a private helicopter for what was a "reasonably short car trip".
The prime minister's office did not comment further on Thursday.
It is standard practice for provision of gifts such as private flights to be declared on the parliamentary members' interests register.
Mr Albanese's register has not been updated since December 19, but he is known to routinely update his listing.
Mr Andrews told reporters on Thursday it was a "private, social event - a barbecue".
"A lot of things get discussed at barbecues ... (and) I will boldly predict it won't be the only barbecue I go to this summer."
He said he had nothing to publicly declare following the event.
"I deal with many people and I deal with everybody appropriately."