Two men have been found guilty of conspiring to supply a controlled drug after police swooped on a suspected £20 million amphetamine factory.

Another man walked free from Lewes Crown Court while the fates of three other defendants hang in the balance as the jury continues its deliberations today.

Kevin Hoare, 46, of Bugsell Mill Oast, Hurst Green, near Robertsbridge, and Graham Pierce, 41, of Greyswood Street, Streatham, London, face jail following their convictions for conspiring to supply amphetamine, known as speed, between July 1998 and July 2002.

They also face charges of conspiring to produce the drug, along with Kevin Hoare's son, Adam, 19, of Princes Plain, Bromley, his girlfriend Tracey Thacker, 35, of Vicarage Way, Hurst Green, and Alan Smith, 52, of Frewin Close, St Leonards.

Kevin Hoare's other son, 20-year-old Russell, shook with relief as he was found not guilty of the same charge.

The jury of nine women and three men deliberated for more than three hours yesterday before finding Kevin Hoare and Pierce guilty.

Two hours later they found Russell Hoare not guilty.

The jury was discharged until this morning.

The trial at Lewes Crown Court is now in its sixth week.

The jury heard how police raided a remote barn in Hurst Green and allegedly found one of Britain's biggest drug producing operations.

They estimated amphetamine sulphate worth about £20 million was manufactured over four years.

Detectives raiding the barn discovered vats of chemicals, containers of powder, bottles, pans, funnels and other paraphernalia.

The court heard the chemicals which were found could be used to produce 660 kilos of amphetamine.

In total, 811g of pure amphetamine was found in the barn, estimated to be worth between £5,000 and £150,000, the court was told.

Kevin Hoare, who runs a company making glass scientific products and has no previous convictions, claimed he rented out the barn to a mystery acquaintance, who he believed was making medication to treat cancer.

This man, who Kevin Hoare referred to in court only as Mr A, wanted to keep the work secret because he was concerned about animal rights activists discovering what he was doing.

Kevin Hoare said after a while he started to help Mr A out with the chemical process.

Both Adam and Russell Hoare told the court they believed their father's explanation because he was against drugs, while Adam added that on two occasions he had been asked to carry out a task in the barn, such as take something off a hot plate and put it in the freezer.

The court also heard how Kevin Hoare admitted making deliveries for Mr A but was unwilling to name others involved.

The jury was told Kevin Hoare was arrested on July 18 after delivering a box containing 1 kilo of pure amphetamine to Pierce's London address.

Pierce was arrested on the same day.

Kevin Hoare's financial history was also discussed during the trial.

Up until his arrest, Kevin Hoare claimed he was having to juggle the day-to-day finances.

The case continues.