LONDON: The government is locked in a battle with the media for refusing to say why a notorious child killer has been sent back to jail, amid warnings he faces a "lynch mob" if his identity is revealed.

Newspapers want to know what Jon Venables -- who has been given a new identity -- did to breach his parole on the life sentence he and another boy received for the brutal 1993 murder of toddler James Bulger when they were 10.

Bulger's mother, Denise Fergus, has accused ministers of "closing doors in my face" on the issue.

"As James' mother, I have a right to know," she insisted.

But Justice Secretary Jack Straw has refused to release the information for fear of compromising the anonymity granted to Venables and co-conspirator Robert Thompson.

They risked the "serious prospect of being maimed or killed", he warned.

"We don't have capital punishment in this country. We have never had rule by lynch mob, even when we did have capital punishment," Straw told MPs.

The row has revived painful memories of a murder case that shocked the nation, and sparked a new media assault on the perpetrators of what a former minister described as a "uniquely and unparalleled evil and barbarous act".

In February 1993, two-year-old Bulger was snatched in a shopping centre in Liverpool, tortured and left to die on a railway track.

Venables and Thompson were jailed for life for his murder and ordered to serve a minimum of eight years. They were released on licence in 2001.

Some media reports suggest Venables was found with child pornography prior to his recall to jail in late February.

Others say he is in such a fragile mental state that he has begun telling people who he is.

He and Thompson are among only four criminals ever granted a court anonymity order.

The pair were given this protection because of the level of "moral outrage" at their crime, and the new uproar has sparked similar fears for their safety.

"Society could never get their heads around two ten-year-olds doing this," Venables' former lawyer, Laurence Lee, told AFP.

"If they could commit offences like this at the age of ten, they must've been evil from birth. They've been looked upon as the devil personified."

He had "no sympathy" for Venables but said it was vital he remain anonymous, adding: "If his identity is released he would be lynched."

Elizabeth Butler-Sloss, the judge who gave Venables and Thompson anonymity on their release, also warned of the dangers of revealing too much.

Speaking in parliament this week, she stressed "the enormous importance of protecting his anonymity now and if he is released because those who wanted to kill him in 2001 are likely to be out there now".

The fear is that the public -- and prison staff -- will be on the look-out for anyone who looks like Venables. One man has already been hounded by an Internet and text message campaign that claimed he was the killer.

Lee said Venables and Thompson would have been "looking over their shoulders" ever since their release, adding: "They may be at liberty but they'll never be free."

Some campaigners believe the pair should never have been jailed at all.

Britain is rare in prosecuting children as young as 10, and the United Nations -- which recommends 12 as the minimum age -- has criticised a "general climate of intolerance and negative attitude towards children" here.

Rob Allen, director of the International Centre for Prison Studies, said that in other countries, children who commit crimes "are seen as victims in some ways -- society has failed them".

They are helped by social workers, not jailed, he told AFP. He argued children should not be prosecuted below the age of 14.

However, he said media attitudes had changed since the Bulger case.

In January, two brothers aged 11 and 12 were jailed for at least five years for torturing and assaulting a nine-year-old and an 11-year-old boy in the south Yorkshire town of Edlington last year.

Allen said the press coverage of them was "more balanced", focusing on their chaotic family backgrounds.

The coverage was also helped by the fact that they were never named.