Has another celebrity mentor backed out of The Voice?

After four years as a mentor, will.i.am has reportedly decided to step down for his role  on The Voice UK.

The star of the Black Eyed Peas has been a mentor on the programme since the very first season. Apparently, his decision has come a result of his disappointment with the show not producing any overly successful stars.

According the The Mirror, bosses at the BBC are “desperate” to keep him on the programme, especially since Rita Ora also backed out of her role this year.

A source has reportedly said:

"Will has been in discussions with producers but decided he doesn't want to return this year. He’s disappointed Rita Ora left and is frustrated the show has failed to produce an international star.”

Will is also supposedly upset that his former contestant Leah McFall failed to “set the charts alight”.

There are rumours that American singer Jason Derulo could step in as a replacement for Will. Kaiser Chiefs singer Ricky Wilson is expected to sign on again and there are also plenty of rumours that Kylie Minogue could be making her return in the future.

The Daily Star on Sunday reports that singer Joss Stone, 28, was approached to sign on as a mentor but refused.

A spokesperson for The Voice is reported as saying that negotiations are still ongoing ahead of the series fifth year in production.