Former Russian Double Agent Critically Ill After Exposure to ‘Unknown Substance’ in Britain

A police tent is seen behind a cordon at the scene at The Maltings shopping centre in Salisbury, southern England, on March 6, 2018 where a man and a woman were found critically ill on a bench on March 4 and taken to hospital sparking a major incident. Chris J Ratcliffe/AFP/Getty Images

SALISBURY, England—A former Russian double agent convicted of treason in Moscow was critically ill in a British hospital on Tuesday after exposure to an unknown substance, with police saying it had to be “alive to the fact of state threats”.

In its first response, the Kremlin said it was ready to cooperate if Britain asked for help in its investigation of the “tragic situation”.