A teenage girl, who pinned a woman to the ground during a "vile and horrifying" sex attack, was today found guilty of rape.

Claire Marsh, 18, is thought to be the youngest of the few females ever to be convicted of such an offence in this country.

She punched the 37-year-old victim in the face, called her a "slag", and then ripped off her top before she was gang-raped on a canal towpath.

A 15-year-old boy, who tore off her trousers, then forced the woman to have sex.

Others in the 14-strong group - one aged just 12 - stood around during an shouting encouragement as the sordid scene unfolded shortly after midnight.

When the first youth had finished, Marvin Edwards, 18, also raped her, London's Blackfriars Crown Court was told.

Eventually the screaming victim, who had earlier been hurled into the murky water of the Grand Union Canal in Ladbroke Grove, West London, wriggled free from her attackers, struggled to her feet and made a run for it.

But the woman's desperate bid for freedom was short lived and she was brought crashing to the ground after just a few yards.

The helpless victim - known only as Miss X for legal reasons - was then kicked and punched repeatedly and, at one stage, dragged naked along a gravel path, lacerating her bare skin.

Fearing that if she did not escape she might not survive, she made another run for it.

She was again chased, but this time was more fortunate. A surprised cab driver saw her and then spotted two youths chasing her. And when they saw him they veered away.

The woman, still naked, ran more than a mile altogether, mostly through the all but deserted streets of night-time London. She only stopped when she reached her front door, sobbing hysterically.

Police were called and later found some of her clothing in the canal. The rest were never recovered.

Marsh, of Laleham Walk, Margate, Kent, initially showed no reaction as the seven woman and five men trying her rejected her protestations of innocence and found her guilty of rape on July 22 last year.

But when Judge Timothy Pontius adjourned sentence and rejected a defence application for bail in the interim and remanded her in custody, tears began streaming down her face.

"Given this was a particularly vile and horrifying offence of sexual brutality, a substantial custodial sentence is inevitable," he warned.

To allow her freedom now would entail a risk of her absconding.

She would be sentenced at the Old Bailey on May 8 with Edwards, of Brentford, West London, and 15-year-old who admitted rape at the beginning of the two-and-a-half week trial.

The jury which spent more than nine hours over two days deliberating, cleared a second 15-year-old youth and one aged 16 of the same offence.