Kim Kardashian's worst nightmare could become a reality, with her sex tape ex Ray J set to take part in the new All Stars vs New Stars version of Celebrity Big Brother.

Kicking off on 3 January, show bosses are pulling out all the stops – promising a mixture of former CBB icons and some fresh faces.

Top of their new blood list is singer Ray J, who infamously starred in the homemade blue movie that made 36-year-old Kim become one of the most talked about people on the planet.

Last year saw Kim's best friend Jonathan Cheban enter the notorious Borehamwood bungalow.

While the 42-year-old failed to give much away about his friendship with the Keeping Up With The Kardashians favourite, TV execs are hoping Ray J will.

"Bosses are over the moon with how the negotiations are going," a source told The Sun.

"Kim is one of the biggest celebrities in the world and they were never going to get her – but booking Ray J means they'll get someone with proper insight into what goes on behind closed doors.

"He was right by her side as she shot to fame because of their sex tape, so they are hoping he will talk openly about their relationship and reveal lots of new things about her while in the house."

Ray J – the brother of R&B star Brandy – has previously opened up about Kim in his track Famous, alongside Chris Brown.

The songs lyrics included the line: "Look her in the eyes. She was the first one to sign on the line. She was the real one to plan it all out."

He also didn't hold back in his book Death of a Cheating Man: What Every Woman Must Know About Men Who Stray.

In it, Ray J goes on the record about the relationship, revealing Kim's alleged history of cheating on men, their sex life in bed and her obsessive behaviour.

Ray J and Princess Love
Ray J is now married to reality TV star Princess Love Jonathan Leibson/Getty Images

While Kim is now married to rapper Kanye West, 35-year-old Ray J has found happiness with another reality TV star, Princess Love.

He and the 32-year-old – whose full name is Princess Pilpina Love Norwood – tied the knot in August.

She stars in the US show Love & Hiphop Hollywood.

Meanwhile, Celebrity Big Brother hosts Emma Willis, 40, and Rylan Clark-Neal, 28, have teased that the upcoming series will be "the most colourful yet".

weirdest Eurovision entries
Jedward are among the names being touted to return for the new series of CBB AFP

Previous celeb contestants tipped to return include veteran glamour model Katie Price, Irish twins Jedward, Ex On The Beach bad boy Stephen Bear and acid-tongued former Apprentice star Katie Hopkins.