The BBC's Stephen Cape reports: "Gary Glitter is tonight behind bars"

The admission comes just hours after the rock idol was cleared of eight counts of sexually assaulting a teenage fan nearly 20 years ago.

Solicitor Henri Brandman said Glitter would appeal against the sentence. He will be placed on the sex offenders register.

Reappearing at Bristol Crown Court, Glitter admitted 54 offences of downloading porn from the Internet dating between 3 January 1997 and 18 November 1997.

He replied "guilty" in a strong, clear voice after the first count was put to him and his voice became less clear with each subsequent charge.

The judge, Mr Justice Butterfield, described the pictures in Glitter's vast library as "filthy and revolting" and of the "worst possible type".

Glitter as glam-rock star

The charges came after a member of staff spotted the material on Glitter's computer, in for repair at PC World in Bristol.

Mr John Royce, QC, told the court that a technician tried to correct the fault and in order to see if he was successful had to look into a file. But what he found, said the QC, was "disturbing".

A police sergeant arrested Glitter when he returned to collect his computer.

An initial examination of the computer revealed that it stored "the most appalling images" of very young children engaged in most humiliating sexual acts, said the QC.

The examinations, said Mr Royce, revealed firstly that he had downloaded the material and secondly "that it was carefully, deliberately and enthusiastically done".

More than 4,000 such images, mostly of young girls but many of young boys, were found.

Mr Royce said they showed "very young children, some appeared as young as two, in the main ranging from three, four, five and six up to possibly about nine or 10".

In mitigation the defence said Glitter had downloaded the pictures soley for his own use and was simply in possession of them, but the judge rejected this, saying Glitter had diligently visited sites worldwide.

News of the initial arrest prompted further allegations of assault in a newspaper - dismissed by a jury earlier on Friday.

The singer had always denied four counts of indecently assaulting a girl in the early 1980s when she was under 16.

He also denied four charges of serious sexual assault against the same girl, who is now 34 and married with children.

'Reprehensible'

After the verdict the Press Complaints Commission said it would investigate revelations that a newspaper paid the woman who made the allegations.

The court was told that the woman had taken �10,000 from the News of the World in exchange for her story and would receive �25,000 if the star was convicted.

The judge had branded the pay-out "highly reprehensible". He said: "It is not illegal but it is to be greatly deprecated."

The Lord Chancellor, Lord Irvine, has also called for a full report from the judge over the payments.

Gary Glitter, charged under his real name, Paul Gadd, smiled as the not guilty verdict was greeted by cheers in the public gallery. He turned to the jury, put his hands together and said "thank you".

Suicide threat

She told the News of the World that she had met the artist aged 14 when he invited her on stage and she sang a song with him.

The woman claimed that the friendship, which was encouraged by her parents, developed into a sexual relationship.

The jury was told that during their stormy relationship the star convinced her he was serious about their affair and would threaten suicide if the woman tried to end it.

The woman told the court that she went to the News of the World in 1993 to "get him to leave me alone". She received �10,000 for revealing that he was "bald and a wig-wearer".