Julian Assange isn’t about to walk out of the Ecuadorean embassy in London, despite fresh claims by US officials that he’s unlikely to face charges for publishing top secret documents.

WikiLeaks is sceptical about the latest report, based on comments from unnamed officials, arguing it could be a ruse to undermine support for the Australian.

“Anonymous US officials with obscure motivations and unknown authority do not have a good track record in this matter or in any other,” WikiLeaks told AAP in a statement.

“It remains to be seen whether the claims by these unknown, anonymous officials are more than just an attempt to reduce public support for WikiLeaks.”

The Washington Post has reported that the US Justice Department has “all but concluded” it won’t charge Assange for publishing classified documents because it couldn’t do so without also prosecuting news organisations and journalists.

Officials stressed, however, that a formal decision was yet to be taken and a grand jury investigating WikiLeaks remained impanelled.

WikiLeaks on Tuesday said the fact the Justice Department had admitted its multi-million dollar investigation against Assange continued, proved former foreign minister Bob Carr “repeatedly misled the Australian public and parliament when he claimed otherwise”.

“It is time for the department and the FBI to do the right thing and finally abandon its absurd persecution of the WikiLeaks organisation and start a full and open inquiry into what has taken place,” the website said.

The Washington Post last week quoted US officials saying there was not a sealed indictment against Assange.

But the former computer hacker has long maintained the US has issued such a document as well as a sealed extradition order.

Assange insists he’d be arrested by British police and taken to the US if he left Ecuador’s diplomatic mission.

The 42-year-old has been holed up in the London embassy for 18 months avoiding extradition to Sweden over allegations of sexual assault.

He claimed earlier this year that even if the Swedish investigation was dropped, he wouldn’t leave for fear of being tried in the US.

Assange wants the British government to guarantee him “safe passage” to South America.