RUSSIAN spies have been caught trying to hack into the headquarters of the world’s chemical weapon watchdog.

Dutch military intelligence revealed yesterday that they managed to disrupt a “close access” cyber-attack on the Organisation for the Prohibition of Chemical Weapons (OPCW).

At a press conference, Dutch defence minister, Ank Bijleveld, said four intelligence officials from the GRU’s cybercrime unit, known as Sandworm, had been caught “in flagrante” in a hired car, outside the OPCW’s headquarters in the Hague in April.

In the car Dutch officials also found taxi receipts from a GRU facility in Moscow to the airport and an antenna hidden under a coat.

Working with British intelligence they were able to establish that it had been pointed at the OPCW in an attempt to intercept computer logins via the wifi network.

Investigators also found large sums of cash, laptops, train tickets, passports with sequential numbers and other hacking equipment.

The bungled hack came as the watchdog was investigating the Salisbury novichok poisoning and the chemical attack on Douma, Syria.

Though the head of Dutch counter-intelligence, Onno Eichelsheim, said they couldn’t say for sure that the attempted assassination of former Russian double agent Sergei Skripal and his daughter Yulia.

“We have concluded they targeted the OPCW during the period that the OPCW was occupied with the Skripal investigation, but we have not been able to prove that they targeted the OPCW because of the Skripal investigation.”

The Dutch said the laptops found in the car yielded proof of previous attempts to hack investigations in Malaysia into the downing of MH17, and in Switzerland thought to be on the World Anti-Doping Agency.

The British said they also had evidence of attempted attacks on the Porton Down chemical weapons facility in April and on the UK Foreign Office in March.

A joint statement from the British prime minister, Theresa May, and her Dutch counterpart, Mark Rutte, said: “The GRU’s reckless operations stretch from destructive cyber-activity to the use of illegal nerve agents, as we saw in Salisbury.

“That attack left four people fighting for their lives and one woman dead.

“Our action today reinforces the clear message from the international community. We will uphold the rules-based international system, and defend international institutions from those that seek to do them harm.”

The shadow chancellor, John McDonnell, called for tougher state action against Russian individuals. “If there is hard evidence that we can accuse the Russians of activities in our country which are unacceptable and even criminal, we have to hit them where it hurts: in the pocket.

“If we use our financial penalties effectively, that’s the way we can end the threats that we have from Russia at the moment.”

Russian foreign ministry spokeswoman Maria Zakharova dismissed the hacking accusations as “big fantasies”.

Asked about accusations from the Foreign Office of Russia being involved in worldwide cyber attacks, a spokesman for the Russian embassy said: “This statement is reckless. It has become a tradition for such claims to lack any evidence.

“It is yet another element of the anti-Russian campaign by the UK Government.

“In December 2017 during the then-foreign secretary Boris Johnson’s visit to Moscow, Russia’s Foreign Minister Sergei Lavrov proposed to launch expert consultations on cybersecurity in order to address UK’s concerns, if any. The offer was turned down. The only reasonable explanation is that the UK has no facts for a substantive discussion.

Johnson’s successor, Jeremy Hunt, said the Russian government needed “to know that if they flout international law in this way, there will be consequences”.