WESTERN allies have joined forces to expose Vladimir Putin’s global cyber-warfare strategy, including a botched attempt to hack into the international chemical weapons watchdog.

Whitehall sources revealed how a UK-Dutch operation in the Netherlands caught four Russian spies “in flagrante” as they tried to hack into the Organisation for the Prohibition of Chemical Weapons in the Hague.

The incident happened in April, just weeks after its laboratories were examining the Novichok used in the Salisbury poisoning, and led to the expulsion from Holland of a four-man team from Russia's GRU military intelligence service.

In Washington, the US indicted seven people for “malicious cyber-activities,” including the four men expelled from the Netherlands; three others were among those charged in July with hacking Democratic officials during the 2016 US elections.

John Demers, the US Assistant Attorney General for National Security, said the attacks were Russian retaliation for the bans on its country’s athletes following evidence it was systematically using drugs to enhance their performance.

In a joint statement, Prime Minister Theresa May and Mark Rutte, her Dutch counterpart, condemned the Kremlin’s "unacceptable cyber-activities" and vowed to work to uphold the "rules-based international system". Jeremy Hunt, the Foreign Secretary, made clear Russia could face further sanctions.

But Moscow dismissed the allegations as "Western spy-mania".