Julian Assange is engaged and fathered two children while seeking asylum in the Ecuadorian embassy, according to his organisation, WikiLeaks.

Key points: Stella Morris was part of Julian Assange's legal team when he was fighting sexual assault charges in 2011

Stella Morris was part of Julian Assange's legal team when he was fighting sexual assault charges in 2011 She said she went to the Ecuadorian embassy "almost every single day" once Assange started living there and they started a relationship in 2015

She said she went to the Ecuadorian embassy "almost every single day" once Assange started living there and they started a relationship in 2015 She said a security firm tried to steal the used nappy of one of her babies to try to ascertain whether it was Assange's child

In a video posted to YouTube, Stella Morris said she met Assange in London in 2011 when she was assisting Australian human rights lawyer Jennifer Robinson with Assange's case in Sweden, where he was accused of sexual assault.

That case has since been dropped.

Ms Morris said the pair started a relationship in 2015, when Assange was in the Ecuadorian embassy and her fluency in Spanish came in handy on the case.

"I had been in the embassy almost every single day and got to know Julian very well, and in 2015 [we] got together," she said.

Stella Morris said she met Julian Assange in 2011 and started a relationship with him in 2015. ( YouTube: The WikiLeaks Channel )

"We fell in love and this is a person that I knew well by then … the person I know the most in this world.

"He's extraordinary, he's generous and he's very tender and loving."

She said starting a family was "a deliberate decision" to give Assange a light at the end of the tunnel while he was in what she described as a "prison" in the embassy.

"For many people it would seem insane to start a family in that context, [but] for us it was the sane thing to do, it was what keeps things real," she said.

"And it grounds me. When Julian sees the children it gives him a lot of peace and nurturing and support, and that's good. They're happy children."

Security firm wanted baby's dirty nappy for paternity test

A recent court case revealed Assange had been spied on and UC Global, the Spanish company contracted to provide security at the embassy, tried to ascertain the paternity of a baby that had been brought into the building when the mother would visit Assange.

In December 2017, UC Global owner David Morales allegedly directed an employee to steal a used nappy of the baby to DNA test faecal matter to establish if the child was Assange's son.

The employee refused the directive and told an English court he instead decided to tell the mother.

"When we were outside of the embassy, I told her that she must not take the child to the embassy anymore because they planned to steal her baby's diapers to prove whether he was the son of Julian Assange," the employee said.

Ms Morris addressed that interaction in the Wikileaks video.

"You try to insulate it [the family] and protect it as fiercely as you can," she said.

"Even if I took all these steps — more steps than most people — to try to preserve our privacy and our security and Julian's safety, ultimately in a way it was beyond my control and that was very difficult to realise."

The video was released on the first anniversary of Assange's arrest in England after living in the embassy for seven years to avoid extradition to Sweden.

Last April, Assange was found guilty of failing to surrender to the court. He has been in custody since then.

In May he was sentenced to 50 weeks in jail for breaching bail conditions by living in the Ecuadorian embassy, and Ms Morris said she was not sure how to explain it to the children.

"You want them to feel positive feeling about going there as well, so it's a bit of a charade," she said.

Assange is still fighting to avoid extradition to the US, where he faces 17 charges of espionage and one charge of conspiring to commit computer intrusion, having allegedly conspired with Chelsea Manning to leak hundreds of thousands of secret documents almost a decade ago.