The Daily Mail reported on Saturday that Stella Morris, a South African-born lawyer and Swedish national, started a relationship with Assange in 2015 and the two have been engaged since 2017.
Morris has said their children — Gabriel, aged 2, and his one-year-old brother, Max — were conceived while Assange was hiding out to avoid extradition to the United States, where he faces espionage charges over the leaking of thousands of classified US intelligence documents.
The couple, as the British newspaper reported, managed to keep their relationship secret from the Ecuadorean staff and diplomats, who for seven years gave the Australian whistle-blower refuge at the embassy.
Morris said she had decided to reveal the relationship and the existence of their sons because she feared for the life and health condition of her fiancé. Assange has been in a high-security prison in London since the Ecuadoran Embassy expelled him a year ago.