Representatives for Cousins Law Firm in West Palm Beach, Florida lodged the paperwork with Prince's estate, claiming the company are owed around $600,000 (£485,000) for their services.

Patrick Cousins tells TMZ.com the outstanding bill dates back to the singer's 2006 divorce from second wife Manuela Testolini and they had an agreement the Purple Rain star didn't have to pay it off until all the loose ends were tied up, although he wouldn't reveal what the "loose ends" were.

He claims they finished up on 1 April (16), just weeks before Prince died on 21 April (16) from a fentanyl overdose, aged 57.

Prince had married Testolini in 2001.