Ferne reportedly hooked up with Russell for the second time earlier this year, and when asked about the 40-year-old in a recent interview, Ferne was full of compliments.
She told The Mirror: "I think he's a great guy. He's very intelligent, very sexy."
Ferne's comments follows reports two months ago that she and Russell, who used to be married to pop star Katy Perry, enjoyed a 'secret tryst' earlier this year.
A source told the newspaper that Ferne and Russell bumped into each other backstage during a taping of The Jonathan Ross Show in in May and swapped numbers.
"They've met up several times since and she went to his house in East London," said the insider. "The pair exchanged countless flirty messages. It was definitely 'on' for a while but it was only a casual thing."
This is the second time that Ferne has been linked to Russell. Reports first emerged in November 2013 that the pair had been on a string of secret dates.
Dismissing reports, Russell tweeted at the time: "I have literally never seen this human."
However, Ferne's BFF Sam Faiers then tweeted a picture of Ferne and Billie with Russell showing that the pair had met at least once.
Ferne also spoke out at the time, saying: "The whole thing that has come out about Russell Brand and me happened a long time ago. I will not be meeting up with Russell in LA or at any time in the future. And we haven't been in touch."
Try Reveal's digital edition on iPhone & iPad. Subscribe now & never miss an issue!