Fresh claims over Bulger killer Jon Venables' recall
Jon Venables served eight years for murdering James Bulger
Jon Venables - one of the killers of James Bulger - was recalled to prison on suspicion of offences related to images of child abuse, a paper reports.
The Sunday Mirror also claims Venables, who was released on licence with a new identity in 2001, had sparked concerns by using drugs and revealing his past.
Justice Secretary Jack Straw said he faced "extremely serious allegations".
James Bulger's mother, Denise Fergus, said Venables should lose his anonymity if he is charged with serious offences.
Labour's Deputy Leader, Harriet Harman, told the BBC the government would not be drawn on the report.
"I'm not saying whether it's true or not because I don't want to comment on it," she said.
"At the time that Venables was sentenced, it was said that he should keep his anonymity and, as a general principle, we want to make absolutely sure that nobody can get off a criminal offence by saying 'I can't get a fair trial, there's been too much publicity'."
Venables, now 27, served eight years for the murder of two-year-old James.
Harriet Harman: "I don't want to jeopardise the criminal justice system"
He and Robert Thompson - both aged 10 - became the UK's youngest murderers after abducting the two-year-old from a shopping centre in Bootle, Merseyside, in February 1993.
Since the news broke on Tuesday that Venables had breached his licence and had been returned to jail, ministers have refused to release details of his alleged offence.
On Wednesday, the Home Secretary Alan Johnson said he believed the public "had a right to know" why Venables was back in jail.
But Mr Straw said secrecy was in the public interest, and he was later backed by the prime minister.
However, Mr Straw did reveal in a statement on Saturday that the allegations against Venables were "extremely serious".
"I said on Wednesday that I was unable to give further details of the reasons for Jon Venables' return to custody, because it was not in the public interest to do so," he said.
"We all feared that a premature disclosure of information would undermine the integrity of the criminal justice process, including the investigation and potential prosecution of individual(s).
"Our motivation throughout has been solely to ensure that some extremely serious allegations are properly investigated and that justice is done."
A report in the Sun newspaper on Saturday claimed Venables was alleged to have committed a serious sexual offence.
James Bulger was abducted from a shopping centre in Bootle
BBC home affairs correspondent Danny Shaw said government solicitors had attempted to prevent the Sun publishing full details of the allegations against Venables.
Meanwhile, Mrs Fergus said Venables should face any charges under his real name.
Speaking on behalf of the 42-year-old before the Mirror published its claims, her spokesman Chris Johnson said she was "appalled" by Venables' return to jail.
"She doesn't think that he should be at liberty anyway," he said.
"He should really have served a sentence of something in the order of 15 years and should be coming up for parole now.
"In her mind, if there has been an offence committed, it means that that could have been avoided."
Mr Straw's office has been in contact with Mrs Fergus and she is hoping to have a meeting with the justice secretary this week, but she is not expected to be told the reasons for his recall to custody.
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