MARY-KATE OLSEN fled a weekend screening of The Dark Knight just 20 minutes in, because she couldn't bear to see HEATH LEDGER on the big screen.

Sources say the 22 year old, who was romantically linked to the tragic actor at the time of his death in January, felt sure she'd be OK during the film, but scenes of Heath as the Joker in the new Batman film upset her too much.

She attended a screening in Century City, California with friends six months to the day of Ledger's death, but left soon after the film began.

A pal says: "It got to be too much for her. She wanted to go unnoticed, but people recognised her and started whispering. She felt really weird.

"Between dealing with Heath onscreen and with everyone around her, she couldn't take it. So she left."

Ledger died from an accidental drug overdose and Olsen was dragged into the riddle surrounding his death when it emerged she was telephoned from the scene of the tragedy before emergency services.