Wikileaks founder Julian Assange is set to plead guilty in a deal with the US authorities and return to Australia, it has been reported.

According to the Associated Press, court papers filed by the US Justice Department show Assange is scheduled to appear in federal court to plead guilty to an Espionage Act charge of conspiring to unlawfully obtain and disseminate classified national defence information.

It followed the publication of hundreds of thousands of leaked documents relating to the Afghanistan and Iraq wars.

He is expected to return to his home country of Australia after his plea and sentencing, scheduled for Wednesday morning local time in the Mariana Islands, a US commonwealth in the Western Pacific.

Assange had been locked in a lengthy legal battle in the UK over his extradition, which included him entering the Ecuadorean Embassy in London in 2012 prior to his detention in Belmarsh prison.

In a January 2021 ruling, then-district judge Vanessa Baraitser said Assange should not be sent to the US, citing a real and “oppressive” risk of suicide, while ruling against him on all other issues.

Later that year, US authorities won a High Court bid to overturn this block, paving the way towards Assange’s extradition.

Assange was due to bring his own challenge to the High Court in London in early July after he was recently given the go-ahead to challenge the original judge’s dismissal of parts of his case.

Assange has been in custody at HMP Belmarsh for more than five years, fighting a lengthy legal battle against extradition to the United States.