WikiLeaks founder Julian Assange fathered two children with one of his lawyers while holed up in Ecuador's embassy in London for much of the past decade, according to a report Sunday confirmed by the mother.

The 48-year-old Australian is the dad of two boys, aged two and one, with lawyer Stella Morris, to whom he is engaged, she confirmed following a Mail on Sunday report.

Assange is currently being held in London's high security Belmarsh prison as he fights an extradition request by the United States to stand trial there on espionage charges.

Morris detailed the revelations shortly after the report emerged, in a video posted on social media by Wikileaks chronicling her five-year relationship with Assange and the arrival of their two children. 

"We fell in love," she said in the nearly 12-minute film, outlining how the romance began in 2015 -- three years into his seven-year stay at the Ecuadorian embassy in central London.

"This is the person... I know the most in this world -- he's extraordinary," the South African-born lawyer said.

Morris said she wanted to speak out now fearing Assange's life "might be coming to an end" due to his continued detention and the spread of coronavirus.

Jennifer Robinson, one of Assange's lawyers in Britain who introduced the pair to each other in 2011, according to Morris, also confirmed to AFP they were a family.

She said a statement by Morris outlining the situation had been cited as evidence in a failed court bid last month to get Assange bailed to avoid catching COVID-19.

"Despite her statement about their family and the medical evidence about the severe risk to Assange's health, the judge refused bail and refused to grant her and the children anonymity," Robinson said.

The British government plans to allow some prisoners temporary release, amid fears COVID-19 could sweep through jails, but a judge rejected the request on March 25, saying there were "no grounds" for his release.

'Deliberate decision'

Assange faces charges under the US Espionage Act for the 2010 release of a trove of secret files detailing aspects of US military campaigns in Afghanistan and Iraq.

A ruling against Assange could see him jailed for 175 years.

He ensconced himself in the Ecuadoran embassy in 2012 after skipping bail to avoid separate legal proceedings in Sweden, but was finally dragged out last year.

He reportedly conceived the first child with Morris in 2016, according to the Mail on Sunday.

Morris said the couple began a relationship the previous year while she was visiting him to work on his legal cases.

Assange watched the birth of both children in London hospitals via live video-link and met the elder boy, named Gabriel, after he was smuggled into the embassy, the newspaper said.

It published the report alongside photographs of Assange with the toddlers.

Both boys are said to be British citizens and have reportedly visited their father in prison as well as the embassy previously.

"Forming a family was a deliberate decision to kind of break down those walls around him and imagine a life beyond," Morris said.

"While for many people it would seem insane to start a family in that context, for us it was the sane thing to do.

"It grounds me and when Julian sees the children it gives him a lot of peace, and nurturing and support."

Assange's full extradition hearing is due to resume for three weeks in mid-May, when witnesses will be called and cross-examined, with an eventual ruling expected by August at the latest.

But proceedings could be delayed as court hearings have been affected by the coronavirus outbreak.