18:04

The location where the nerve agent novichok was developed and produced is a closed town in central Russia, Shikhany, according to a chemical weapons expert, Hamish de Bretton-Gordon.

Shikhany is the Russian equivalent of Porton Down, home to various research facilities that deal with radiation and chemical weapons.

He said the information was disclosed in a report sent by the Russians to the international body responsible for monitoring chemical weapons, the Organisation for Prohibition of Chemical Weapons.