Britney Spears was restrained by police and taken to hospital after a dispute involving her two young children.
Reports say she held her two sons hostage for almost 4 hours when she was under court order to hand them back to Kevin Federline.
Police were called to her house and she was then taken by ambulance to hospital for psychiatric evaluation.
They have said Britney was under the influence of an unknown substance.
K-Fed, the children and Spears father are said to be at the Cedars Medical Centre where the Piece Of Me singer is being held.