By Chris Summers
Two drug barons have been convicted of conspiracy to pervert the course of justice. They have been jailed for a total of 42 years but how did they manage to hoodwink HM Customs, a High Court judge and the then home secretary Michael Howard?
Jul 1993 - John Haase (pictured) and Paul Bennett arrested in London on serious drugs charges and remanded in custody
Oct 1993 - They begin a massive gun planting operation
Dec 1994 - Gun smuggled into HMP Strangeways, shortly before the end of Thomas Bourke's trial
Aug 1995 - After pleading guilty Haase and Bennett are jailed for 18 years in open court on drugs charges
Jul 1996 - Haase and Bennett walk free, after secretly receiving the Royal Prerogative of Mercy
Oct 1999 - Haase is arrested again for drug trafficking and later jailed for 13 years
Mar 2007 - Haase is charged with perverting the course of justice
Nov 2008 - Haase and Bennett jailed for 22 and 20 years respectively
When someone is jailed for 18 years in open court the general public would be surprised if they were freed 10 months later.
But that is what happened to Liverpool gangster John Haase and his nephew Paul Bennett, thanks to a secret deal which was signed off by the then home secretary Michael Howard.
Now, following their conviction for perverting the course of justice, it has become clear the pair hoodwinked the entire establishment, including Mr Howard, Judge David Lynch and HM Customs.
What is worrying, according to Labour MP Peter Kilfoyle, who investigated the whole affair, is that no safeguards have been introduced in the last 12 years to prevent other criminals manipulating the system in the same way.
Graham Johnson, an investigative journalist and the author of a book on the Haase case, said: "This goes on all the time with supergrasses. It began before Haase and it is still going on."
Mr Howard himself told the BBC: "People try to deceive judges all the time and it's quite difficult to devise a system which would be foolproof when it comes to deceiving judges."
The story began in the summer of 1993 when Haase and Bennett were arrested, along with several Turkish drug smugglers, in connection with a consignment of 60 kilos of pure heroin.
Knowing they faced a long stretch in jail they approached Customs officials with an offer to tip them off about other criminals' activities.
The then home secretary Michael Howard signed off on the deal
They agreed with surprising ease, considering Haase had a criminal record dating back to 1964 and was one of Merseyside's 'Mr Bigs'.
Equipped with mobile phones in their jail cells and using a war chest of cash from their drug trafficking activities, the pair concocted a plan in which accomplices on the outside bought guns and then planted them all over Liverpool and north west England.
Haase and Bennett would then tip off the authorities, pretending they had heard about other criminals' activities on the grapevine, and in some cases hinting at the involvement of the IRA.
They even arranged for a gun to be smuggled into Strangeways prison in Manchester.
Haase then suggested the gun had been brought in for Thomas Bourke, a garage owner from Stockport who was on trial for the murder of two MOT inspectors.
Bourke had nothing to do with it but security was stepped up around his trial and his sister, Jo Holt, believes this influenced the jury, which convicted him. Bourke continues to protest his innocence.
At Haase and Bennett's trial at Southwark Crown Court Judge Lynch said he was influenced by the report from their handler, Customs officer Paul Cook, who said: "It is highly unlikely that they would revert to a life of crime upon their release."
Judge Lynch told the trial he would never have recommended the Royal Prerogative if he had any suggestion the information they supplied was "tainted".
After their release in July 1996 Haase and Bennett were offered places on the witness protection scheme and the judge said he understood they were to get new identities and be relocated to South America.
Instead they returned to their native Merseyside and resumed their criminal careers. News of their release soon broke in the Liverpool Echo and the Sunday Mirror and questions were asked in Parliament.
Thomas Bourke, who is still in jail, was wrongly accused of smuggling the gun
Haase set up a security firm but was jailed again in 1999 for drugs offences. In 2004 Peter Kilfoyle persuaded him on a visit to Whitemoor Prison to make a sworn affidavit in which he admitted planting the guns.
Mr Kilfoyle later took the affidavit to Her Majesty's Inspectorate of Constabulary and they asked Scotland Yard to begin an investigation. Operation Ainstable was launched in 2005 and Haase and several other people were charged. Bennett was later extradited from Portugal.
They went on trial in October and Gibson Grenfell QC, prosecuting, said: "This case is concerned with a manipulation of the criminal justice system whereby John Haase and his nephew Paul Bennett, who knew they were facing very long terms of imprisonment, set out to and did secure a large reduction in that sentence by providing information to the authorities which was in highly important respects false."
Detective Sergeant Keith Bright told the trial: "I believe they expected it all to remain secret and it was only due to the media outcry that it became public."
Bennett, who was extradited from Portugal, was jailed for 20 years
On Wednesday Haase, 59, was jailed for 22 years and Bennett, 44, locked up for 20 years. Haase's wife, Debbie, was given a four year term and her friend Sharon Knowles locked up for five years.
Detective Superintendent Graham McNulty said: "Haase was devious, manipulative. To pull this off as a Category A prisoner shows a degree of sophistication and a cunning nature."
He said the informant system had changed considerably since the 1990s and new guidelines had been brought in on the handling of "supergrasses".
But Mr Kilfoyle said there was a need for a full and independent inquiry and a review of other supergrass cases to see if similar scams had been pulled.
"There are huge lessons which need to be drawn from this about how we treat informants and how the courts deal with information from them," said Mr Kilfoyle, who hopes to air matters in a debate in Parliament next week.