Russia's ambassador to the European Union has suggested a nerve agent that poisoned a former spy in England could have come from a British lab.
Vladimir Chizhov says Russia has no chemical weapons stockpiles and was not behind the poisoning of Sergei Skripal and his daughter Yulia.
In comments broadcast Sunday, Chizhov told the BBC that the U.K. chemical weapons research facility, Porton Down, is only eight miles (12 kilometers) from Salisbury, where the Skripals were found earlier this month.
Asked whether he was saying Porton Down was responsible, he replied: "I don't know."
The British government says Chizhov's suggestion is "nonsense."
Meanwhile, Russia's ambassador in London, Alexander Yakovenko, called for "cooler heads." He told the Mail on Sunday that the dispute is "escalating dangerously and out of proportion."
- EXPULSIONS OF DIPLOMATS
Chezhov refused to clarify whether he was suggesting that the Porton Down was responsible of the nerve agent used in Salisbury. "I don't know. I don't have any evidence of anything having been used," he said.
Former Russian spy Sergei Skripal, 66, and his daughter Yulia, 33, were admitted to a hospital on March 4 after being found unconscious in Salisbury. The incident also saw a British police officer injured seriously.
British Prime Minister Theresa May said last Monday that it is "highly likely" that Russia was behind the attack in conclusion that came after tests carried out at the Porton Down military facilities.
Britain expelled 23 Russian diplomats, a move Russia responded by expelling the same number of British diplomats from Moscow in a reciprocal action.
Meanwhile, British Foreign Office said there was "not an ounce of truth" in Chizhov's suggestion of a link to Porton Down.
"It's just another futile attempt from the Russian state to divert the story away from the facts - that Russia has acted in flagrant breach of its international obligations," a spokesperson said.
The ambassador's remarks came after Russian Foreign Ministry commented that the U.K. could be the source for the Novichok nerve agent used in Salisbury alongside with some other countries such as Czech Republic, Slovakia, Sweden and possibly the U.S.
Russian Foreign Ministry's spokesperson Maria Zakharova said a number of ex-Soviet scientists had left Russia, "taking with them the technologies that they were working on."
- 'SATIRICAL CLAIMS'
British Foreign Secretary Boris Johnson described Chizhov's claims as "satirical". He said it "is not the response of a country that really believes itself to be innocent".
Also speaking to the BBC, Johnson said experts from the Organisation for the Prohibition of Chemical Weapons (OPCW) will arrive in the U.K. on Monday to carry out tests on the samples of the nerve agent used in Salisbury.
In a separate statement, the British government said the invitation to OPCW experts by Prime Minister Theresa May "reflects the UK's commitment to fully complying with the obligations of the Chemical Weapons Convention."
"The Foreign Secretary revealed this morning that we have information indicating that within the last decade, Russia has investigated ways of delivering nerve agents likely for assassination," the statement said.
"And part of this programme has involved producing and stockpiling quantities of novichok. This is a violation of the Chemical Weapons Convention," it added.
Sergei Skripal was granted refuge in the U.K. following a spy exchange in 2010 between the U.S. and Russia. Before the exchange, he was serving 13 years in prison for leaking information to British intelligence.
The incident has drawn comparisons to the fate of former KGB agent Alexander Litvinenko, who died in 2006 after drinking radioactive tea. Former KGB bodyguards, identified as suspects in the murder, denied any involvement.
