Billy Bob Thornton calls Amber Heard affair rumours 'completely false'

Billy Bob Thornton has addressed rumours he had an affair with Amber Heard, calling them 'Johnny Depp's fantasy'. Photo / AP

Billy Bob Thornton has slammed reports that he had an affair with Amber Heard as "completely false", saying he had to assure his own wife the claims were just Johnny Depp's fantasy.

Thornton, 61, who has been married five times before, was forced to explain to his current wife Connie Angland that the story was just "Depp's fantasy", TMZ reports.

The denial came after it was revealed that Depp, 53, allegedly cut the tip of his finger off during a rage and dipped it in blue paint to write the words 'Starring Billy Bob and Easy Amber" on a mirror.

Both Amber Heard, pictured, and Billy Bob Thornton have denied Johnny Depp's reported claims of an affair. Photo/Getty

Thornton and Heard have shot a movie called London Fields, which is set to be released later this year. They had also worked together in the 2008 film The Informers.

However, Thornton told TMZ that not only did he not sleep with Heard but that the pair had no friendship and did not hang out together off set except for one cast dinner.

Thornton has been married to long-time love Angland since 2014, with whom he has a daughter Bella, born in 2004.

The pair started dating not long after his split from Angelina Jolie in 2003. He had earlier started dating Jolie without even breaking up with former love, Laura Dern.

Heard is also claiming in court papers that Depp did not have the finger treated until almost 24 hours after he sliced off the top of the digit, and that doctors had to use a flap of skin from his hand to fashion a new tip.

Heard also states in the filing that she never had a sexual relationship with Thornton, and claims that Depp frequently accused her of sleeping with other men during their relationship.