An investigation into why two police forces in Britain failed to bar Ian Huntley from working with children despite allegations against him of underage sex and rape has been ordered by Home Secretary David Blunkett.
Checks by Cambridgeshire and Humberside police failed to reveal the numerous allegations as Huntley alternated between using his mother's maiden name of Nixon and his own.
"Real concerns exist about the way in which police intelligence about Huntley's past was handled," Mr Blunkett said in a statement.
"I am determined that we should uncover the full facts through this independent inquiry."
Humberside police Chief Constable David Westwood apologised for the mistakes, saying an investigation had revealed "some system failings and elements of human error".
His force had had 10 contacts with Huntley over a four-year period, in relation to eight sex-related allegations.
Chief Constable of Cambridgeshire Police Tom Lloyd said he welcomed the Home Office inquiry.
"It's easy to look back and say things could have been done differently but ... we know that we could not have saved those two girls," he told reporters.
Local MP James Paice said people needed answers as to why the checks had not revealed Huntley's past and why he had not been charged with any crime despite a "damning list" of allegations.
North East Lincolnshire council admitted that it had investigated five allegations against Huntley - four of underage sex and one of indecent assault.
"He was described to us as the boyfriend of some of the young women, for varying, but short periods of time," the council said in a statement.
"Four of the young women declined to make a complaint about him. The case of the fifth young woman was investigated by the police and no prosecution followed."
The cases were never linked the authority said because they had occurred in different places across the local area.
It had not alerted Cambridgeshire council or the police because he was never prosecuted.
"Even with the benefit of hindsight when we have reviewed the cases where Huntley was mentioned there is nothing that would suggest he would go on to commit these crimes," it said.
PA