Johnny Depp has accused Amber Heard of being unfaithful with Elon Musk a month after they got married.

The 55-year-old actor has filed a $50 million defamation lawsuit against his ex-wife following an article she wrote for the Washington Post newspaper, in which she identified herself as a domestic abuse victim, and in his legal papers, the 'Pirates of the Caribbean' star claimed the 32-year-old actress embarked on a ''new relationship'' with the Tesla founder in March 2015.

The lawsuit stated: ''Unbeknownst to Mr Depp, no later than one month after his marriage to Ms Heard, she was spending time in a new relationship with Tesla and Space X founder, Elon Musk.

The 'Danish Girl' star hasn't commented on the infidelity accusation, but her lawyer has branded the lawsuit ''frivolous'' and an attempt to ''silence'' the actress.

Meanwhile, Johnny's team are confident they can prove his allegations are true.

They hit back: '''They want to silence Amber Heard' doesn't sound like denial by Ms Heard of Mr Depp's 40-page, evidence-packed complaint.

''We hardly intend to silence Ms Heard--to the contrary, we intend to subpoena and compel evidence from her, her three hoax-assisting friends, and Elon Musk.

''We look forward to holding the overwhelming video, photographic and eyewitness evidence we finally possess up against Amber Heard's (so far silent) attempts to explain the inexplicable.''