The officers, who had served on the National Crime Squad, were trapped by the secret operation.

Sergeant David Redfern, 42, was jailed for running a drugs den at the home he shared with his mistress, Nicola Bladen.

Fellow Derbyshire police officer Sergeant Mark Jennison, 41, was sentenced to 12 months imprisonment after being found guilty of supplying and being in possession of drugs.

Jennison impersonating Freddie Mercury for charity

A total of nine defendants caught by the undercover operation were sentenced at Northampton Crown Court on Friday.

The court heard the group used the house in Derbyshire to take and share drugs with a serving prisoner and members of the public.

Judge Charles Wide QC passed sentence on all nine defendants, jailing Derbyshire Police Sergeant Redfern for three years nine months.

He had admitted supplying and possessing drugs.

Heather Bossart, 40, of Nottinghamshire Police was sentenced to 100 hours community service for possession of cocaine.

Jennison and Bossart were both serving with the National Crime Squad at the time of their arrests in April 2001.

Redfern and Bladen were caught on camera

The arrests followed the covert Operation Lancelot when fellow officers set up the camera at the house in Hilton after becoming suspicious.

That camera recorded Bladen, who was jailed for two years for possession and supply of cocaine, and Redfern and others snorting cocaine.

Judge Wide, QC told Redfern and Jennison said: "You more than most should know the harm that drugs can do.

"In exposing yourselves to criminals you compromised yourselves as police officers.

I am disappointed that these officers have brought the force into disrepute Bob Wood, Derbyshire's deputy chief constable

"Drugs, particularly class A drugs, are a social curse. People who deal in drugs must expect custodial sentences."

Detective Superintendent Russell Day, of the National Crime Squad, said following the hearing: "This case demonstrates what happens when police officers let the public down.

"While we are pleased that all nine defendants have today been sentenced, this is tinged with shame and embarrassment."

Redfern and Jennison were dismissed from the Derbyshire force and Bossart was allowed to resign from the Nottinghamshire force.

Deputy chief constable of Derbyshire, Bob Wood said: "I am disappointed that these officers have brought the force into disrepute.

"The Derbyshire officers involved in the court case today have faced disciplinary action and have been dismissed from the force."