By Chris Summers
Paul Bennett was jailed for 20 years
An MP has called for an independent inquiry into the case of two drug barons jailed for 20 and 22 years for perverting the course of justice.
Labour MP Peter Kilfoyle told the Commons the case had highlighted major flaws in the criminal justice system.
John Haase and Paul Bennett were given a form of pardon in 1995 after tricking officials into believing they had given information about guns on Merseyside.
The Ministry of Justice said it would consider the merits of an inquiry.
The pair were granted a Royal Prerogative of Mercy by the then Home Secretary Michael Howard after posing as supergrasses and tricking HM Customs and a judge into thinking they had provided crucial information.
Mr Kilfoyle, MP for Liverpool Walton, followed up rumours about Haase for 12 years and finally met him in prison, where he persuaded him to write an affidavit in which he virtually confessed to what he had done.
That played a part in his conviction last week.
Mr Kilfoyle said the Haase affair proved that criminals were "far from stupid" and some of them were capable of manipulating the justice system.
In an adjournment debate in the House of Commons on Tuesday, Mr Kilfoyle said: "The Customs were duped, the police were duped, the Home Office were duped and the judiciary were duped, and all by two career criminals.
"But nobody in government has ever accepted responsibility for this - like it was an act of God."
Mr Kilfoyle added: "I'm told that procedures have changed in Customs and the police and I frankly don't believe it.
"Until someone reviews what took place in this scandal, I fear that all we are going to do is pass time until we have a repeat."
Peter Kilfoyle obtained the confession in 2004
Mr Kilfoyle said: "There needs to be a full and open and independent inquiry into this case, which strikes at the very heart of the criminal justice system."
Maria Eagle, a junior minister in the Ministry of Justice, who also represents a Liverpool constituency, congratulated Mr Kilfoyle on his "tenacious" pursuit of Haase and Bennett and said he had been thoroughly vindicated by their convictions.
She pointed out that the Royal Prerogative had been issued only five times since the Haase and Bennett case, and the most recent case was in 2002.
She said since the introduction of the Serious and Organised Crime Police Act, there were now much better ways of rewarding supergrasses and she insisted that other reforms meant there was a reduced chance of a repeat of the Haase affair.