I felt a surge of electricity
The 35 year-old housemate says the pair slept together in a hotel near the Big Brother studios back in 2006.
Lauren claims they met when Russell was hosting Big Brother’s Big Mouth and she was asked to be a guest on the show.
I knew it would take a man with real awareness and strength to take me on
Antiques child progidy Lauren, formerly James, who has been living as a woman for 12 years, told a UK newspaper: 'I felt a surge of electricity. I had sex with Russell.'
Claiming she was nervous about Russell coming over after filming the show, she added: 'I knew it would take a man with real awareness and strength to take me on.'
She said the comedian – who has openly admitted to being a sex addict – had flirted with the throughout the Big Brother spin off show, calling her ‘my sexy cow.’
In a blog called The Affair, Lauren said that when Russell found out she would be staying in a nearby hotel, he said: 'Fancy a drink?'
She later tweeted: 'I had sex with ruseell brand in one of endemol's cheap hotel's - Although Russell thinks he's Jesus - believe me girls, he's not.'
Russell, who is currently promoting his Messiah Complex World Tour, has yet to shed any light on the claims.
But the star has been open about his battle with fidelity during his marriage to singer Katy Perry, recently comparing being married to like being a monk.
During the UK-leg of his stand-up tour, the 37 year-old said: 'When you're married, it's one person. That's one more than a monk. It's not that different', before cheekily adding: 'I'd be having sex thinking, "think of anyone, anyone else"'.