It's not unheard for a Prime Minister to call a press conference on a weekend, but the heads up given to journalists before Anthony Albanese's appearance on Saturday raised eyebrows. 

The PM's office alerted journalists to an event involving Mr Albanese, Minister for Indigenous Australians Linda Burney and … NBA legend Shaquille O'Neal. 

Why was Shaq at an Australian press conference?

It was after a meeting that Mr Albanese said was O'Neal's idea. 

The basketball legend was in Australia and wanted to discuss the government's Indigenous Voice to Parliament referendum. 

"He is interested in this country," Mr Albanese said. 

"He knows that we are a warm and generous people, and he wanted to inform himself about what this debate was about by engaging directly with the Minister for Indigenous Affairs and myself as the Prime Minister."

How did that meeting go?

"It was a terrific meeting," Mr Albanese said. 

Ms Burney said it was "wonderful" to meet O'Neal. 

"I'm really pleased and very proud that Shaq has sought a request through the Prime Minister to specifically talk about the plans that we have in relation to a referendum," she said.

"He said it was a noble task, that it was important."

Mr Albanese gave O'Neal two jerseys from his favourite rugby league team, the South Sydney Rabbitohs, and Ms Burney gave him a boomerang handmade by First Nations artist Josh Evans.

What did O'Neal say?

He wasn't there to answer questions from the reporters and only appeared briefly at the beginning of the press conference. 

However, he shook hands with Mr Albanese and Ms Burney and said a few words for the cameras. 

"I'm here in your country, whatever you need from me, just let me know," O'Neal said.

"We all know Shaq loves Australia."

Was bringing in Shaq part of the government's plan?

It doesn't sound like it.

Mr Albanese was asked if he was surprised by O'Neal's interest.

"He approached us and people who organised his visit to Australia, and we responded very positively to it," Mr Albanese said. 

"I think having Shaquille O'Neal as part of a campaign is important, but it is also extremely important that we build support across the community," Ms Burney said. 

"It was just so wonderful to meet him and to see that there is international interest from people like Mr O'Neill in relation to the project that we have underway about the referendum."

So what is the referendum about? 

It's about deciding whether to change the constitution to establish an Aboriginal and Torres Strait Islander Voice to Parliament. 

On Saturday, Mr Albanese said work was still being done to determine what that would mean. 

"It will recognise First Nations people, Aboriginal and Torres Strait Islander people in our constitution, which at the moment is a gap," he said. 

"Secondly, it will make it clear that they should be consulted to a Voice on matters that affect them.

"Thirdly, it makes clear through the draft wording that it's not a third chamber, it's not something that usurps the power of parliament.

"It is something that will be subservient to legislation in the parliament."

When will the referendum be?

A date hasn't been set yet. 

However, Mr Albanese has committed to a national vote in his first term as Prime Minister.