Denise Richards refuses to care for Charlie Sheen and Brooke Mueller's four-year-old twins any longer.

The 42-year-old star, who was granted temporary custody of her ex-husband's sons, Bob and Max, in May until the end of this year, after their mother's drug use spiralled out of control, said she can't continue to provide a home for the boys as they are violent towards her own children and dogs.

The actress, who has two daughters, Sam, nine, and Lola, eight, with Charlie, as well as an adopted daughter Eloise, two, wrote a distressing letter to the Los Angeles County Department of Children and Family Services (DCFS), blaming Brooke for her sons' behaviour.

A source told gossip website that Denise said the boys often go into a ''zombie-like state'' and gave details about their violent behaviour, including one incident that saw Bob throw a toy at Sam's face forcing Denise to take her to the doctor.

The former 'Bond' girl also claimed that Bob and Max have been acting out in school since they started in September, harming other children and slapping their teachers.

The blonde beauty said that Brooke has blocked her from trying to seek psychological counselling for the boys.

Denise's damaging letter backs up Charlie's claims that his sons freak out after spending time with their mother.

Brooke and the 'Anger Management' star have been locked in a bitter custody battle since her release from rehab this autumn, with Charlie branding the 36-year-old blonde an ''evil and pathetic uber loser'' in a rant about her on Twitter last week.

The troubled socialite is preparing to go to court about Charlie's comments as everyone involved in the custody and guardianship cases has been ordered not to discuss the situation.