Frank Ocean has reportedly demanded that Travis Scott remove his vocals from 'Carousel'.

The 30-year-old rapper is believed to have filed a cease and desist against his fellow hip-hop star asking him to take action and have his bit of the song dropped from his record, 'Astroworld', because he's not allegedly not happy with unknown ''changes'' that he claims were made on the final cut of the song.

According to gossip website TMZ, the 'Blonde' hitmaker has got lawyers involved and if Travis - who is in a relationship with Kylie Jenner - refuses to remove his vocals from the record, Frank will have no choice but to sue the rapper.

Neither of the artists have publically addressed the issue and it no doubt comes as a shock to their fans who were full of praise of the collaboration.

This is the second legal case for Frank this year.

In February, he filed action against producer Om'Mas Keith, who he hired in 2014 to produce master recordings for his 'Blonde' album.

Frank had stated Om'Mas registered with ASCAP - an organisation which manages royalties for songwriters - and claimed he had co-written 11 songs, including 'Ivy' and 'Pink + White'.

The 'Thinkin Bout You' hitmaker paid the producer - who also worked on his 2012 debut LP 'Channel Orange' - a flat fee to work on the master recordings and insisted he had no part in writing the lyrics, melody, or music for any of his songs.

He then asked a judge to block Om'Mas from getting songwriting credits.

However, he was counter-sued by the producer in May.

Frank's lawyer, Ed McPherson, said at the time: ''Mr. Ocean stands behind everything that we alleged in the First Amended Complaint, and we look forward to having the case heard by a judge and jury. We are confident that, when the true facts are presented, Mr. Ocean will prevail. It is quite telling that, on the list of the many songs that Mr. Keith claims to have co-written is a song called 'At Your Best (You Are Love),' which was written and recorded by the Isley Brothers in 1975, and covered by Aaliyah in 1994.''