On a tape released by the Los Angeles Fire Department, the unidentified male caller tells a switchboard operator that repeated attempts to revive Jackson via CPR had been unsuccessful.

The caller also tells the operator that Jackson's personal doctor - who was reportedly being sought by police on Friday - was the only witness to the star's collapse.

The following are excerpts from the exchange:

CALLER: 'We have a gentleman here that needs help and he's not breathing.

He's not breathing and we're trying to pump him, but he's not -

OPERATOR: 'OK. How old?'

CALLER: 'He's 50 years old, sir.'

OPERATOR: 'He's not conscious, he's not breathing?'

CALLER: 'He's not breathing.'

OPERATOR: 'And he's not conscious either?'

CALLER: 'Not conscious, sir.'

OPERATOR: 'OK. Alright. Is he on the floor, where is he at right now?

CALLER: 'He's on the bed, sir.'

OPERATOR: 'Let's get him on the floor.'

CALLER: 'OK.'

OPERATOR: 'Let's get him down to the floor. I'll help you with CPR right now. We're on our way. We'll help you on the phone. Did anybody see him?

CALLER: 'Yes, we have a personal doctor with him, sir.'

OPERATOR: 'And you have a doctor there?'

CALLER: 'Yes, but he's not responding to anything. He's not responding to the CPR or anything.'

OPERATOR: 'Oh, OK. We're on our way there. If your guy's doing a CPR instructed by a doctor, you're a higher authority than me. Did anybody witness what happened?

CALLER: 'No. Just the doctor, sir. The doctor's been the only one here.'

OPERATOR: 'So the doctor was there? Doctor, did you see what happened, sir?

CALLER: 'Please -'

OPERATOR: 'We're on our way. I'm just asking the questions for the paramedics while they're on their way.'

CALLER: 'He's pumping the chest but he's not responding to anything, sir, please.'

OPERATOR: 'We're on our way. We're about a mile away. Be there shortly.

CALLER: 'Thank you, sir.' -- AFP