Sharon Stone sharonroan.jpgSharon Stone has lost physical custody of her 8 year-old son Roan, whom she adopted with ex-husband Phil Bronstein.

According to court documents from a September 12 custody hearing obtained by Entertainment Tonight, Phil Bronstein "shall have permanent sole physical custody of child. Court finds that Respondent (Sharon Stone) failed to meet her burden of proof and denies Respondent's (Sharon Stone's) request for modification of custody."

The 12th minute order contradicts the October 2007 custody order that awarded joint legal and physical custody to Stone and Bronstein.

The decision is permanent unless there is a change of circumstances.

What circumstances? What's prompting Bronstein to seek removal of the child from his adoptive mother's custody?

X17online is told by a source close to Stone that Bronstein was unhappy with the home environment she provided for Roan. According to our source, Stone's house is very often a party place for the actress and her girlfriends and that there is an "inappropriate sexual atmosphere."

Bronstein was seeking custody only for Roan, as Stone's two other sons, Laird and Quinn, were adopted after the couple's divorce in 2004.