A man accused of setting up one of the largest illegal drugs labs in the UK was helped by a cartel including his two sons, a court heard.

Lewes Crown Court heard how Kevin Hoare, 46, had a part in producing more than £20 million-worth of amphetamine sulphate, known as speed, from the lab at his remote country farm at Bugsell Mill Oast Hurst Green.

He was helped by his two sons, Adam and Russell Hoare, both 20, of Princes Plain, Bromley, and Alan Smith, 52, of Frewin Close, St Leonards, who all lived on the farm at the time.

Other members of the cartel included Graham Pierce, 41, of Greyswood Street, Streatham, and Tracey Thacker, 35, of Vicarage Way, Hurst Green, who was Kevin Hoare's girlfriend at the time, All except Pierce are charged with conspiracy to produce amphetamine between July 1998 and July 2002.

Kevin Hoare is charged with producing a controlled drug between July 1998 and July 2002. He and Pierce also face charges of conspiring to supply amphetamine between August 1999 and July 2002.

The court heard that while the formula used to produced the drugs was not very technical, it was not as simple as a Delia Smith recipe.

Police swooped on the farm on July 18 last year and said they found vats of chemicals in the process of being turned into the drug, pure amphetamine in a fridge and freezer, and substantial quantities of lactose, which can be added to the drug before it is sold.

Christine Laing, prosecuting, said the total weight of pure amphetamine "just lying around" in the barn when police swooped was 811g. When cut to a street purity of five per cent, it would be worth between £50,00 and £150,000.

Chemicals found in the barn would have been cap-able of producing up to 660kg of amphetamine.

In total, she said it was estimated the laboratory had produced between two and six tonnes of amphetamine sulphate with a value of at least £20 million.

Miss Laing said: "This activity often continued well into the night. The chemical compounds were turned into amphetimines. It was then cut down to saleable quantities.

"The drug is usually cut down with glucose, caffeine, or lactose. These items were found at Kevin Hoare's laboratory at the barn.

"The drug was put in plastic bags so it could be sold. The completed product from start to finish was undoubtedly being made by all defendents, with the exception of Pierce."

Miss Laing said Thacker was arrested in the barnduring the police swoop.

She said: "She was wearing white plastic gloves and stirring a pot of something used in the process of making amphetamine.

"When she was arrested in the barn and cautioned she replied: 'Oh my God, how naive, I didn't know they were drugs'.

"She said she had been told they were making discs for cancer patients. She said she thought the process was rather strange.

"We are not talking about street-user quantities but the other end of the scale. The production of very large quantities of amphetamine sulphate and supply of that drug over three to four years.

"This is one of the largest illegal drug operations to have been uncovered in this country."

Pierce and Kevin Hoare were remanded in custody.

The trial continues.