A suspect in the killing of PC Sharon Beshenivsky in Bradford last year was a foreign criminal that officials failed to remove because it was too dangerous to return him to his home country.
The disclosure that Mustaf Jamma, a Somalian on the run from police, had been considered for deportation is a damaging new blow to Charles Clarke as he attempts to draw a line under the recent prisoner-release scandal.
The Home Secretary will make an emergency statement to MPs today on the crisis and faces an investigation over the fiasco both by the Parliamentary Ombudsman and a separate Commons committee.
Although Jamma was not one of the 1,023 foreign inmates who were released without a deportation hearing, his alleged involvement in PC Beshenivsky's death raises difficult new questions for the Government over its penal and immigration policy.
Jamma, a repeat offender, was released from prison in spring last year. His case was examined at that point but officials did not order his deportation because Somalia, much of which is run by feuding warlords, is considered highly dangerous.
About six months later, PC Beshenivsky, 38, was shot dead as she investigated a reported robbery at a travel agency in Bradford. She left a husband, three children and two stepchildren.
Police have warned that Jamma may have tried to leave the UK. Posters and leaflets with his details have been were distributed to ports and airports. Five other men are in custody awaiting trial for murder.
Home Office sources stressed that the allegations against Jamma were separate from the storm over the 1,023 prisoner releases.
But the latest disclosure is a gift to opposition parties who believe the Government's reputation on law and order has been ruined.
Nick Clegg, the Liberal Democrat home affairs spokesman, said: "As long as Charles Clarke is prevented from assuming political responsibility for this chaotic state of affairs, he will continue to be buffeted by one allegation after another."
David Davis, the shadow Home Secretary, said there were now a "whole set of new questions" about the thousands of foreign offenders allowed to remain in the country.
Mr Clarke, who is fighting a desperate battle to hold on to his job, will appear before the Commons today. Last week, he disclosed that five foreign prisoners who were released without deportation being considered had committed fresh offences.
His appearance, on the eve of tomorrow's local elections, is earlier than ministers had wanted, but Mr Clarke bowed to overwhelming political pressure.
Home Office officials, who admit parts of the department are in "near meltdown", were working into the night to compile the latest figures to be reported.
The sense of crisis engulfing Mr Clarke was heightened by the announcement that the Home Affairs Select Committee, chaired by the former Home Office minister John Denham, would investigate the crisis. It will summon the Home Secretary for a cross-examination that is likely to last several hours - that is if he is still in post after the cabinet reshuffle which is expected within days.
Ann Abraham, the Parliamentary Ombudsman, also signalled that she was prepared to examine the foreign criminals issue as a prime example of government "maladministration".
The problems piled up for Mr Clarke yesterday after it emerged that detailed rules about deporting foreign prisoners were issued to prison governors more than a year ago.
Although the Home Secretary insists he knew nothing of the crisis until last July, a 90-page Prison Service circular set out a strict timetable for considering each foreign prisoner for deportation. Issued on 31 March 2005, it described a fail-safe system to stop cases slipping through the net.
Harry Fletcher, assistant general secretary of the probation union Napo, said: "This Prison Service order makes it clear that procedures have been in place for over a year.
"The problem is that there are insufficient staff in the criminal justice system to carry out the work to a satisfactory level."
n The Civitas think-tank calculates that nearly 700 of the 1,023 offenders released are likely to commit fresh crimes within two years. Its calculations are based on Home Office data which suggests a reconviction rate of 67.4 per cent.
A department in chaos
* January 2004 Chief Inspector of Prisons Anne Owers warned of lack of "procedures to manage deportation or repatriation".
* May 2004 The Prison Reform Trust warned of "poor co-ordination" between the prison and immigration services.
* December 2004 Charles Clarke succeeds David Blunkett as Home Secretary.
* July 2005 The National Audit Office protested over the failure to deal with foreign criminals. According to Clarke, this was when the Home Office began drawing up an action plan.
* November 2005 Sir John Gieve, then the Permanent Secretary to the Home Office, told MPs that since 2001, 403 foreign nationals had been released without deportation proceedings.
* February 2006 According to Downing Street, Ministers now learned that, despite their efforts, foreign prisoners were still being freed without being considered for deportation.
* 25 April The Home Office admitted that 1,023 prisoners escaped deportation hearings over seven years, including 288 since August. Charles Clarke apologised and privately offered to resign. Tony Blair turned him down.
* 28 April Clarke admitted that five out of the 79 "most serious' offenders had since been convicted of other crimes.
* 30 April Tony Blair said whether Clarke stayed in his job "depends on what happens".
* 1 May The Home Office admitted that Clarke knew the problem on 30 March, but delayed three weeks before telling the PM.
Five questions the Home Secretary must answer
* How many more crimes have been committed by offenders who should have been considered for deportation? Will victims be compensated by the Home Office?
* Why did the Home Office ignore repeated warnings, dating back to 2004, on the issue of foreign prisoners?
* Why did releases continue - and accelerate - after July when Mr Clarke says he became aware of the problem?
* Why did it take three weeks for the Home Secretary to inform Tony Blair of the extent of the prisoner releases?
* Why did the police hunt for the 'missing' offenders not begin in earnest until the crisis became public?Reuse content