Image copyright Getty Images Image caption Julian Assange has been living at the Ecuadorean embassy under asylum since 2012

A US judge has postponed ruling on a legal bid to unseal reported criminal charges against Wikileaks founder Julian Assange.

A free-press advocacy group wants to see the documents after their existence was apparently let slip by prosecutors in another case.

But prosecutors and the judge noted that US charges are never ordinarily released until after an arrest.

Prosecutors did not confirm or deny any such charge sheet against Mr Assange.

Image copyright Getty Images Image caption US prosecutors have said a filing mentioning charges against Mr Assange was a mistake

Barry Pollack, a US lawyer representing Mr Assange, told the BBC he is unaware of the nature of such a criminal complaint.

In a federal court on Tuesday in Alexandria, Virginia, Judge Leonie Brinkema called it "an interesting case, to say the least", according to US media.

She said she would make a ruling at a later date after receiving more information.

Lawyers for the Reporters Committee for Freedom of the Press, which filed the motion to unseal, said that since Mr Assange knows he has been charged, there is no rationale for keeping the criminal complaint sealed.

But Assistant US Attorney Gordon Kromberg said that in any legal case, "discussion of why it would be sealed cannot be done in a public forum", the Washington Post reported.

The purported criminal complaint emerged earlier this month when papers from the Eastern District of Virginia federal court stated "Assange has been charged", though he was not listed as a defendant in that case.

A spokesman for the US attorney's office told the New York Times the filing was "made in error".

Media playback is unsupported on your device Media caption In May 2017, Julian Assange spoke on the balcony of the Ecuadorian embassy: "Seven years of detention without charge"

On 16 November, the Reporters Committee for Freedom of the Press filed its motion requesting Judge Brinkema unseal the complaint against Mr Assange.

Its director, Bruce Brown, said in a statement: "There's no longer any justification for keeping the criminal complaint, the docket, and other filings related to the prosecution sealed."

Although prosecutors have said an erroneous reference was not proof of any actual charges, several US media outlets have cited sources as confirming there is a sealed complaint against Mr Assange.

On Tuesday, the Guardian reported that Mr Assange had met former Trump campaign chairman Paul Manafort several times before the 2016 US election.

US investigators are scrutinising whether the Trump campaign was aware of Wikileaks' role in the leaking of Democratic emails that were allegedly stolen by Russian hackers during the American presidential race two years ago.

Mr Manafort swiftly denied the Guardian report.

"This story is totally false and deliberately libellous," said a statement issued through his spokesman.

"I have never met Julian Assange or anyone connected to him."

Wikileaks also denied on Twitter that any such meetings had taken place.

Mr Manafort was convicted of financial fraud earlier this year as a part of special counsel Robert Mueller's investigation into alleged Russian election meddling.

On Monday, the Mueller team said the former aide had breached his plea deal by repeatedly lying to the FBI.

CNN reports that Mr Mueller is also investigating whether Wikileaks or Mr Assange were discussed during a 2017 meeting between Mr Manafort and Ecuadorean President Lenin Moreno.

Mr Assange took refuge in Ecuador's embassy in London in 2012 amid fears he could be prosecuted for Wikileaks' previous revelations of US national security secrets.

Friction between Mr Assange and the diplomatic staff is known to have risen.

According to some reports, he has been asked by the embassy to begin paying his own living expenses from December and has to clean the bathroom.

His lawyers say his physical and mental health has deteriorated in recent months.