Rapper P Diddy has sparked rumours that he is joining the cast of Downton Abbey after tweeting that he had become a "series regular" on the BBC show.

The 43-year-old, real name Sean Combs, told fans how he had a sneak peak of his role on the set of Downton and posted a spoof video of himself in the show.

In the video, he described Downton as his "favourite show of all time". "Last week it was reported that they have cast the first black cast member," he said.

"The only problem with this is I already broke down that barrier. I'm the first black cast member and I've got the scenes to prove it."

In the film, Diddy arrives at Downton and meets members of the household. He introduces himself as Lord Willcot, the "new owner of Downton".

US broadcaster PBS refuted Diddy's claim, with spokeswoman Carrie Johnson telling Reuters: "It's not true."

This is not the first time Diddy has made a film pretending to be a character in a popular entertainment series.

In 2008, the music producer said he wanted to be the first black James Bond and made a short "audition tape" of himself as 007.

Introducing his audition, he said: "I feel like I am best suited to be the next James Bond.

"I've been out there getting my hustle on in Hollywood - I just landed a role on CSI: Miami. We have a black president and it's time for there to be a black Bond."

In the film, which also promotes his fragrance I Am King, Diddy is shown on a yacht lounging in a silk gown, and in a helicopter.

Downton has become hugely popular in the US, with the first episode of the third series drawing 7.9 million viewers.