The revelation that the nerve agent used in the attempt to murder two Russians in Salisbury was an organophosphorous compound, Novichok, recalls one of the most harrowing and shocking stories I have covered as a journalist.

Over 15 years from 1992, I gradually uncovered how the terrifying power of organophosphates (OPs) lay behind a horrendous tragedy, brought about by our own Government. In the Eighties, thousands of farmers suffered a mysterious form of ill health after freeing their sheep from parasites by dipping them in OPs on Government orders.

These highly toxic chemicals, originally developed as an insecticide in Nazi Germany, attack the nervous and immune system, producing a wide range...