A convict who was previously jailed for killing a teenager in a car crash has had his latest term behind bars for running a home-grown cannabis farm with his dad backed by top judges – despite his protests it was too harsh.

Sam Edwards, 34, was jailed for seven and a half years at Aylesbury Crown Court in December 2015 after jurors convicted him of producing “skunk” cannabis.

This came after he was previously jailed for five years in December 2010 for causing the death of 18-year-old Thame man, Greg Stiles, by dangerous driving.

His father, Terry Edwards, 69, was handed a seven-year term for his role in the drugs operation.

Edwards was prosecuted after police raided a property owned by his father in Marsh, in the Great and Little Kimble parish, where Edwards was living at the time.

They discovered a “large scale cannabis factory” containing 1,600 plants - with a potential yield worth around £1.3m on the streets.

The farm was run in a “highly professional” style, Judge Neil Bidder QC told London's Appeal Court today.

The “lucrative commercial venture” was motivated by greed, and prosecutors said Edwards and his father were “jointly running this business”.

Edwards, of no fixed address, argued his role in the enterprise had been exaggerated. He was neither a “financier” nor involved in "onward supply", he insisted.

But Judge Bidder, sitting with Lord Justice Treacy and Mr Justice Stuart Smith, ruled that Edwards’s sentence was fair.

The crown court judge was entitled to find that Edwards “played a leading role”.

“We don’t consider this sentence to be wrong in principle or manifestly excessive”, concluded the judge, dismissing the appeal.