A MAN handed over the keys to a massive cannabis factory after a police officer caught him with dope, a court has heard.

Andrew Clay, 53, gave up the keys to a barn containing 1,080 cannabis plants, after Pc Andrew Wild found an ounce of ‘weed’ in his caravan.

Opening Clay’s trial at St Albans Crown Court on Monday, prosecutor Sarah Porter said police were called, on March 5 last year, by a motorway worker who noticed a strong smell of cannabis between Junction six and seven of the northbound A1(M).

When Pc Wild arrived, he scaled the embankment and spotted a brick outbuilding, the windows of which were covered with black bin bags. He returned to his car and headed for the property, in The Avenue, Welwyn.

As well as the outbuilding and a house there was a caravan, in which he could see movement.

He told jurors when Clay opened the caravan door, he detected an “overpowering” smell of cannabis.

He said he then asked Clay if he had any drugs, to which the defendant replied: “Yes, I have a little bit, can I get it?”

Clay returned with a small bag containing an ounce of dope.

He was arrested on suspicion of possession of a Class B drug, an offence to which he pleaded guilty before the trial.

After his arrest, Clay gave the barn keys to Pc Wild, who recalled: “We went inside and there was a very large number of tables with what appeared to be cannabis plants growing on them.

“There was also a very bright light and fans on the desks which were working.”

Clay told Pc Wild he was looking after the barn for others, in return for the caravan accommodation.

Edward McKiernan, defending, suggested Pc Wild had interviewed his client while he was under the influence of alcohol and drugs.

But the officer denied this, describing Clay as both “coherent” and “amenable”.

Mr McKiernan also claimed that, by allowing the defendant into the barn, Pc Wild could have caused the crime scene to be cross-contaminated.

Pc Wild refuted this and told the court Clay was handcuffed and therefore could not have come into contact with any of the fans or tables.

Clay, of The Avenue, denies being concerned in the production of a Class B drug.

The trial continues.