THE caretaker of a series of wartime tunnels near Kidderminster – where police found a cannabis factory with a crop valued at £70,000 – must have known about the illegal enterprise, a jury has been told.

But Wayne Robinson, aged 48, of Marlpool Lane, Kidderminster, who had been caretaker of the Drakelow Tunnels in Wolverley, since the 1990s, claims to have had no idea that cannabis was growing there.

He told police he had rented part of the premises to two men and he understood they were storing car parts there.

Robinson denies allowing the production of a controlled drug at the tunnels while he was concerned in the management of the site on November 27 2013.

The jury at Worcester Crown Court has been told that the case is a retrial against Robinson.

Timothy Boswell, prosecuting, told the court that the Drakelow Tunnels dated from wartime and had a number of entrances, one of which had a large, steel fortified door.

He said police who broke through the door had discovered a large-scale commercial cannabis factory, with nearly 900 plants growing in the tunnels, which could produce a yield of up to £70,000.

Mr Boswell said Robinson ran a firewood business next to the tunnels and the site was owned by his brother.

In the complex, police had found a number of rooms and the main one – measuring 70ft by 16ft and 20ft high – contained 600 cannabis plants within a few weeks of reaching maturity, with 86 high-powered lights on a timer and eight water tanks.

The set-up would have taken a “significant amount” of building work and electricity was being extracted through a diversion so that the power company would not detect it, added Mr Boswell.

There were more plants, at different stages of growth, in other rooms and Mr Boswell described it as a “crop rotation system”, saying it was set up to generate hundreds of thousands of pounds.

Robinson was arrested and told police he had “no idea” cannabis was being grown there.

But Mr Boswell told the jury: “Those who set this up would take an extraordinary risk when the landlord was not in on what was going on.

“If the landlord discovered this, those in charge would risk losing thousands of pounds of investment and being charged themselves.

“He is the caretaker and, no doubt for some kind of financial reward, allowed the cannabis factory to operate.”

The trial continues.