Terrence Howard accuses ex-wife of witness tampering

Terrence Howard has accused his ex-wife of witness tampering amid allegations she tried to intimidate the actor's sister-in-law to keep her reported extortion plot a secret.

The Iron Man star has been fighting Michelle Ghent over her spousal support demands ever since their one-year marriage fell apart in 2011.

Their divorce was finalized in 2013, but Howard subsequently fell behind on his monthly payments and racked up debts of $50,000 .

A judge granted Ghent another year of spousal support in March (15), but Howard is seeking to have the order overturned amid allegations his ex has been trying to blackmail him with naked photos and threatening to spread rumors suggesting he gave her a sexually transmitted disease if he refused to meet her demands, which includes a cut of his earnings from hit TV drama Empire.

Howard has now filed new court documents to back up his case, including a declaration from his sister-in-law Yvonne.

Yvonne claims the actor's ex spilled all about her alleged exploitation plot against the star, but when it was revealed that she would be testifying on Howard's behalf, Ghent reportedly tried to convince the woman not to take the stand.

Yvonne also reveals Ghent intimidated her to keep their conversation secret, according to TMZ.com.

Howard, 46, is now married to his fourth wife Miranda, and they are expecting their first child together.