A nasty child support case is brewing between Charlie Sheen and ex-wife Brooke Mueller.

Mueller, 38, is accusing the troubled star, 50, of owing $89,000 in back child support, according to People. She claims he’s only paid $21,000 for both March and April and is seeking the remaining balance.

Back in March, Sheen filed papers requesting his payments for the couple’s twin 6-year-old boys, Bob and Max, be reduced from $55,000 a month.

At the time he said his income had been reduced since the original deal was struck in 2011. He was once earning $613,000 a month as the star of “Two and a Half Men,” but his income was slashed to $87,384 a month after leaving the show.

Last fall, Sheen confessed to being HIV positive and was accused of sleeping with women without disclosing his status.

A request for comment from Sheen’s rep wasn’t immediately returned.

This article originally appeared in the New York Post's Page Six.