Charlie Sheen has become embroiled in a lawsuit involving his former mother-in-law.

According to legal documents obtained by TMZ, the 47-year-old star is allegedly being subpoenaed to testify in a lawsuit filed by his ex-wife Brooke Mueller's mother Moira Fiore over the purchase of the 'Anger Management' actor's house.

Fiore claims she hasn't been given 25 per cent commission she was promised by real estate agent Marty Trugman - who has issued the subpoena for Sheen to testify - but he told the gossip website he didn't promise to give her any money.

But Sheen believes Fiore - who claims the former 'Two and a Half Men' star gave her authority to find an abode - should give any money she receives to him or his and Mueller's three-year-old twins Bob and Max.

Mueller has been named as a key witness by both Fiore and Trugman.

But earlier this month, the 35-year-old mother-of-two left rehab for the 19th time after just six days in the treatment facility for drug addiction.

During Mueller’s latest stint in rehab Sheen’s second ex-wife Denise Richards stepped in to look after Bob and Max.

Speaking after Mueller had checked out of the treatment facility, the 'World is Not Enough' actress - who has daughters Sam, eight, and Lola, seven, with Charlie, as well as adopted Eloise, 18 months - said: "[The twins] are back with Brooke Mueller.

"This is not the first time I've had all five, they're Sam and Lola's brothers. It was a full house, lots of love and life. Brooke knows anytime, and Charlie, that any time they need help with the boys, that I'm there."