Peaches Geldof reportedly stopped breathing after an alleged drugs overdose.
The 19-year-old - whose mother Paula Yates died of a heroin overdose in 2000 - was given mouth-to-mouth resuscitation by a friend before paramedics arrived to her London home on Sunday afternoon (20.07.08).
The TV presenter, the daughter of musician-and-activist Bob Geldof, was brought back to consciousness but refused to go to hospital because she was terrified her father would out.
A source told Britain's The Sun newspaper: "Peaches could not breathe for several minutes after suffering a respiratory arrest. Her friend had to give chest pumps and mouth-to-mouth resuscitation.
"If she had not received this she could have died or she could have suffered brain damage. Peaches had gone into respiratory arrest, in which a patient's breathing stops but the heart doesn't.
"It was extremely serious and there is no doubt her friend saved her life."
Another source added: "No one could believe this has happened to Bob Geldof's daughter, particularly considering what happened to her mother."
Peaches - who is dating singer Faris Badwan from The Horrors - is believed to have got angry with the medical team who helped her. The source added: "When she came to she started mouthing off and told the ambulance crew, 'You have to respect my privacy.' She then told them to get out.
"And she refused to go to hospital to have further treatment because she was worried about it getting out." London Ambulance confirmed its crews attended the scene.
A spokeswoman said: "We were called shortly before 4:45pm to an address in London, to reports of a female patient taken ill. Following assessment, the patient did not need hospital treatment."
Both Peaches - who attended the 'A Dark Knight' premiere last night (21.07.08) - and her father have so far refused to comment.