Instead of coming clean, the authorities engaged in what has been described as “one of the biggest cover-ups of the Cold War”.Earlier this year the BBC was given “unprecedented and unique access” to the complex in order to make Inside Porton Down, a look at the workings of one of our most important military and scientific research bases. It was a top secret chemical weapons centre sited on a 7,000 acre site near Sailsbury. After gas masks were distributed to troops on the front line, chlorine became largely ineffective and so the Germans resorted to mustard gas, which soaked into the soldiers’ woollen uniforms and caused terrible blisters and a lingering death.“We use animals in experiments for a purpose – to give our forces the protection they need,” says Lyle. There was no evidence of increased incidents of diseases associated with cadmium toxicity. It was called the The War Department Experimental Research Ground, Porton – but is better known today as Porton Down.But it is keeping abreast of potentially new threats that has always been Porton Down’s raison d’être. Directed by Tim Usborne. Porton Down’s other batch of unwitting guinea pigs was the general public.The Land Rover travelled through Wedmore and on to the outskirts of Bristol.In return for payment and a precious pass for three days leave, soldiers from all over the country travelled to Porton Down to be involved in testing.Despite the extreme safety precautions the scientists took, they were spraying the chemical cloud onto passers-by.The BBC is not responsible for the content of external websitesThe scientists were instructed to handle the chemical very carefully. "We’ve known for quite a while that people were tested inside Porton Down. Over the years it has overhauled its policy towards animal testing. Caught unprepared, he immediately ordered the creation of a chemical weapons laboratory at a remote location in Wiltshire. An experimental biography that explores the disquieting experiences of Don Webb, who found himself unwittingly entangled in a secret British Cold War programme. It is a secret institution that is trying to be more open. Michael Mosley investigates Porton Down, Britain's most secretive and controversial military research base. Michael Mosley investigates Porton Down, Britain's most secretive and controversial military research base. Porton Down is a 'science park' located in Wiltshire, just northeast of the village of Porton, near Salisbury. He comes face to face with chemical and biological weapons old and new.Timings (where shown) are from the start of the programme in hours and minutesDr Michael Mosley investigates Britain's most secretive and controversial military research base, Porton Down, on its 100th anniversary.