A scientist at the heart of the lethal Novichok chemical weapons programme has confirmed a strain of the nerve agent was used to poison a Russian businessman and his secretary in 1995.
Mirror: Scientist who developed nerve agent explosively claims it killed Russian businessman and his secretary

Investigators work in the garden of Sergei Skripal's house in Salisbury, southern England, on March 22, as investigations and operations continue in connection with the major incident sparked after a man and a woman were apparently poisoned in a nerve agent attack in Salisbury on March 4.