Scientists at a Ministry of Defence base in Wiltshire poisoned 223 guinea pigs with deadly nerve agent sarin.
The MoD says the ‘vital’ tests on the animals, who were not anaesthetised, were carried out by scientists at the military science base Porton Down in the battle to find an antidote for sarin, purportedly used by Syrian president Bashar al-Assad in an attack against his own people last August.