A BARN housing Cambridgeshire’s largest haul of cannabis plants was fitted with �200,000 of equipment to get maximum yield from the 7,000 plants, a court heard today (Thursday).

A jury at Cambridge Crown Court was told the ventilation and lighting system at Tree Farm in Haddenham was “typical” of a cannabis farm, with heating and lighting schedules worked out to ensure the plants developed to their full potential.

Kevin Hart, 41, of Elm Close, Huntingdon, is standing trial charged with conspiracy to produce cannabis at the farm, which was uncovered by police last July. He denies the charge.

Dr David Potter, a chartered biologist authorised to cultivate cannabis for medicinal use, told the court on Thursday that he estimated the growing equipment, ventilation and lighting at the barn would have cost around �200,000 to purchase and install.

He said the facilities, with variable temperature and light, could have been used to grow other plants, but that the total reliance on artificial light was typical of cannabis farms.

“That is only done when people are trying to hide what they are doing,” he added.

“All plants need light, air, carbon dioxide and other nutrients, and it was all provided here in this facility – you could grow chrysanthemums in there.

“What clearly marks it as a cannabis facility is that it was hidden from view.”

Hart claims he was unaware that illegal drugs were being grown at the barn, believing the plants to be salvia divinorum, a hallucinatory variety of sage, and says he cut ties with the operation when he found out it was cannabis.

More than 7,000 ‘skunk’ plants were discovered at the barn, a crop which officers estimated to have a street value of up to �3million.

On Wednesday, the jury heard a statement from civil engineer Gerry Cutting, who made an assessment of the premises for Cambridgeshire police following the factory’s discovery.

He noted the barn’s “good management practices”, including lighting for all enclosed corridors, guards on staircases, markings for electrical sockets and fire extinguishers at regular intervals.

A two-tier structure had been built inside the barn to provide more growing space, which Mr Cutting estimated would have taken a three-man team around eight weeks to assemble.

The trial continues.