Up to 80 Britons whose crimes abroad were not placed on police records because of a Home Office blunder could have reoffended in this country, probation officers say.
John Reid moved yesterday to get a grip on the crisis caused by the mistake that allowed 27,500 case files from abroad to gather dust in his department.
The Home Secretary, who faces MPs today, announced a wide-ranging review of how criminal records are held and how to improve the sharing of information about convictions between Britain and other countries.
Meanwhile, an official at the Home Office was suspended in connection with the affair. A spokesman said: "An official at the Home Office has volunteered evidence in the last 48 hours which warrants disciplinary investigation."
The crisis has left a question-mark over the future of two of Mr Reid's ministers, Tony McNulty and Joan Ryan, and cast doubt over his ability to take control of the Home Office.
A massive effort to track down the 540 most serious offenders - including murderers, rapists and paedophiles - was launched last week.
Between 70 and 80 of them could have reoffended in Britain, the National Association of Probation Officers estimated. Others could be difficult to trace because they are living here under different names, it said.
Harry Fletcher, its assistant general secretary, said: "You don't just receive information about highly dangerous people and fail to pass it on. This illustrates once again that the Home Office is too large and needs to be split up."
Opposition parties seized on the case of Dale Miller, who received a 16-year sentence for manslaughter after shooting a man dead in Newcastle in 2000. He had returned to Britain shortly before the killing, having been imprisoned for armed robberies in Germany and Switzerland.
David Davis, the shadow Home Secretary, said: "If this man had been under effective close supervision, his victim may well have been alive today." Nick Clegg, the Liberal Democrat home affairs spokesman, said: "With this disclosure Home Office incompetence has turned from farce to tragedy."
The Home Office rejected the criticisms, insisting that Miller's foreign convictions were known to police.
The department also disclosed that five of the 540 serious offenders - a people smuggler and four people jailed for a year or more for drugs offences - had been cleared to work with children and vulnerable adults.
With information about convictions held by a range of bodies, including the courts, the police and the Criminal Records Bureau, Mr Reid announced plans for a wholesale review of Britain's criminal databases.
Ms Ryan will meet EU counterparts today to discuss improvements in systems for sharing information. She will press for biometric details - especially fingerprints - to be included on future notifications that Britons have been convicted abroad.
* Home Office claims of success in improving criminal justice agencies' performance and cutting crime have been "overstated and are at times misleading", according to a study published today by the Centre for Crime and Justice Studies at King's College London.
Home Office under pressure
* Tony McNulty, Policing minister
The Association of Chief Police Officers (Acpo) wrote to him in October setting out its concerns over the problems entering details of foreign convictions to police computers in Britain.
* Joan Ryan, Immigration minister
The letter was passed to Ms Ryan, who acknowledged it in December. When the foreign case files controversy began, she insisted she knew nothing about it. Two days later she confirmed she had seen the letter.
* John Reid, Home Secretary
He has said it is "inexplicable" that he was not told about the problem, but has defended his ministers over the Acpo letter, saying it contained no explicit warnings.Reuse content