The girl is critically ill with severe burns after being found wandering naked in Stockport, Greater Manchester. She told a passing driver who helped her that she had been kidnapped, drugged, tortured, held for a week then set alight with petrol.
The teenager, who suffered 60- 70 per cent burns, is being treated at Withington hospital.
Greater Manchester police last night successfully applied to Ashton-under-Lyne magistrates for permission to hold four men and two women in custody for a further 24 hours. All six were arrested at a house close to the victim's home in Moston on Tuesday. The application was agreed at a private hearing. The six are being held at separate police stations.
Forensic scientists yesterday examined a house in Langworthy Road, Moston. Neighbours said police arrested five men and two women in the house and later towed a small car from the street.
The officer leading the investigation, Chief Superintendent Ron Astles, said: 'You would have to go back to the days of Brady and Hindley (the Moors Murderers) for an incident that compares with the sheer horror of it. It's an horrific incident. There are distinct reasons behind this and distinct personalities involved.' He ruled out a sexual motive for the attack.
Suzanne's father, John, 53, said last night: 'When I went to the hospital I just couldn't believe it was Suzanne. She looked just like a charred cinder. I felt totally numb - if I could get my hands on these people there's no knowing what I would do.'
Neighbours said Suzanne had become a 'drifter' after Mr Capper and his wife Elizabeth parted about a year ago. Rachel Yeomens, 15, said: 'She never really got over her parents' separation. She was dreading Christmas because she had nowhere to go.'
Lillian Pearson, 46, said: 'A couple of months ago she got in with a bad crowd and started staying at different friends' houses. A couple of weeks ago she described how she had been tied up for four days - but she was inclined to exaggerate and no one believed her.'
The headteacher at the school Suzanne attended until last year said staff and pupils were shocked. John Watkins, of Moston Brook High School, said: 'We saw very little of her from the fourth year onwards because her attendance was erratic. We feel great sympathy for her and we just hope she makes a recovery.'