Four Bradford men have been jailed for a total of 12 years for their part in a plan to import and then sell “massive” quantities of cannabis.

Unknown to them, the four were tailed by undercover police officers as they made their way to Manchester for an arranged meet, where consignments of the drug were handed over.

Packages containing almost 50kg of cannabis – valued at more than £422,000, were later seized.

The West Yorkshire Police operation dubbed “Bizarre”, however, led to the arrest of many others, and the busting of a huge business worth an estimated £60 million.

Six other men who have pleaded not guilty to their involvement, have yet to stand trial later this year.

Troy Bland 34, of Leeds Road, Liversedge; Mohammed Ilyas 33, of Cumberland Road, Girlington, Bradford; Imran Khushall 41, of Hartington Terrace, Lidget Green, Bradford, and Noman Qureshi 31, of Beckside Road, Lidget Green, were each sent down for three years after pleading guilty to a single offence of conspiracy to supply cannabis.

Khushall was sentenced to an additional six months after pleading guilty to possession of a stun gun, which was found disguised as a torch, in his bedroom.

Ilyas was told his sentence will run concurrently with a sentence of eight years and three months imposed only a week ago at Leeds Crown Court where he pleaded guilty to an offence of conspiracy to supply cocaine.

Minshull Street Crown Court in Manchester was yesterday told that the four Bradford men were kept under observation as they met up at the premises of AC Motors in Bradford on December 9, 2011.

Police then secretly followed as they left for Manchester and followed them to an address in Crompton Street, Oldham, where Qureshi and Ilyas waited while Bland and Khushall drove to the arranged meet at a McDonalds restaurant in Mottram in a van.

The pair waited inside while two unidentified men drove the van to a unit on a nearby trading estate.

Officers saw packages of cannabis being loaded into the van, before it was driven back to McDonalds. Bland and Qureshi then drove back to the address in Oldham.

Bland then left alone in the van which was later stopped by police on the M67 outside Manchester.

A search revealed five plastic bags each containing just less than 2kg of cannabis valued at around £85,000. When police searched the address on Crompton Street, they recovered almost 40kg of cannabis valued at £337,960.

The court was told that Bland and Qureshi had claimed to have been couriers acting under the directions of others.

Khushall was said to have accepted that he played a more significant role. He maintained he had the stun gun to protect himself following a violent attack some months ago.

Detective Sergeant Phil Little, of West Yorkshire Police, said: “The defendants’ sentences show that the police will pursue those involved in commercial drugs activity, put offenders behind bars and remove these harmful substances from our communities.”