Rapper 50 Cent has slammed his hip-hop rival Kanye West in a new song - poking fun at the star's decision to sing on his latest album.

West released 808s + Heartbreak last year and debuted a new sound, moving away from his rap roots and showing off his singing skills.

The move was criticised by 50 Cent at the time and now the rap star has incorporated his feelings about West's music in a new track, Heartless Monster, set for release on his upcoming Lp Before I Self-Destruct.

In the song he raps; "It's the return of the heartless monster/I should give you n***ers a whole R+B record/808s and my heart's broken/I hate all these f**kers with the rainbow colours on."