Brown threatened to kill Rihanna

RIHANNA has told police that boyfriend Chris Brown threatened to kill her.

The Umbrella star also claimed that she lost consciousness as he put his hands round her throat during the alleged attack on Sunday.

A source close to the police investigation said R&B star Brown tried to choke her as he screamed: "I'm going to kill you!", after he flew into a rage when she threw away his car keys during an argument.

After he tried in vain to look for them, he returned to the car and put his hands round her throat and she passed out to find he'd fled the scene.

He later turned himself in and was charged with criminal threat and released on bail, although police said more charges may be brought against him.

The source said that Rihanna had a black and badly swollen right eye and hand prints on her arms.

Officers that arrived on the scene were allegedly so concerned about her they drove her straight to hospital in their squad car instead of waiting for an ambulance.

The Los Angeles district attorney has asked police detectives to dig up more evidence for their case against Brown.

It was also revealed that she could be heard "screaming" in the background of the 911 call made to police during the alleged assault.

Police are refusing to release the 911 audio tape to the media but LAPD chief investigator Detective Deshon Andrews said: "It mostly recorded the sound of a screaming woman."

Rihanna has now gone into hiding after cancelling her 21st birthday party and postponing a concert in Malaysia, but sent word to her family in Barbados that she was ok.

Her grandmother Clara Brathwaite told the island's Daily Nation newspaper: "I don't want people to worry. Rihanna is fine and she is doing well."