Duncan Hanrahan, 41, left the Metropolitan Police in 1991 after 14 years and turned informer in 1997 as part of the Met's anti-corruption drive.
Hanrahan had recruited at least four officers to work for cash bribes from criminals.
In one case, two serving officers, a former detective, Hanrahan, and violent criminals planned to use electric stun guns to rob a courier at Heathrow airport of more than pounds 1m.
Despite Hanrahan's confessions and the involvement of at least four allegedly corrupt officers named in court, none of the detectives has been prosecuted because of lack of evidence. Only one officer is still serving and he is off work due to ill health.
Hanrahan, a detective constable who retired on healthgrounds, turned to crime after setting up a business as a private eye. But he and his partner, another corrupt former detective, Martin King, acted as links between criminals and corrupt officers. King, 51, is serving six years for corruption.
Hanrahan also arranged for a raid on a furniture shop in Chiswick, west London, in 1995, where a drug dealer had told him ecstasy was being stored for collection.
The raid was staged by DCChristopher Carter and DS Len Guerard, the court was told. The officers took the tablets valued at pounds 600,000, but told their bosses they had found nothing.
Two criminals sold the drugs in Scotland and Hanrahan was paid pounds 6,000. Carter retired on medical grounds two years ago and Guerard has resigned.
In 1994, Hanrahan and King recruited a criminal gang from Grove Park, south-east London, to rob the courier at Heathrow airport. Carter and Guerard are believed to have given Hanrahan the idea after they investigated the genuine robbery of pounds 1m from a Lebanese courier. The officers even introduced the courier company to Hanrahan, who was described as a security consultant, the court heard.
The plan, which involved knocking the courier out with a stun gun, failed after the courier twice failed to arrive, then the gang quarrelled with the officers.
After Hanrahan turned "supergrass" he failed to tell his handlers of either case, claiming he was afraid of betraying dangerous criminals. The Met's anti-corruption unit, CIB3, had at first believed Hanrahan was a vital witness who could help prosecute other "bent" officers. But they found him a liar who was an unreliable witness.
His downfall came after he boasted about his full exploits to a fellow informer while being held at Parkhurst prison on the Isle of Wight. The informer told his police handlers, who confronted Hanrahan, and further charges were brought.
Hanrahan was originally trapped after he and King offered bribes to a Det Ch Insp Elcock. But the inspector was working with anti-corruption officers and secretly recordedtheir meetings.
Hanrahan, from Tonbridge, Kent, admitted 11 charges of corruption and conspiracies to pervert justice, steal, supply drugs and rob.
Hanrahan is bankrupt and his second marriage, to a police constable, has broken up.Reuse content