Moscow on Thursday accused British secret services of poisoning ex-spy Sergei Skripal in order to discredit Russia.
"British secret services are highly likely to benefit from the provocation of poisoning Russian citizens in Salisbury and, possibly, organized it in order to discredit Russia and its political leadership," Russian Foreign Ministry spokeswoman Maria Zakharova told a news briefing.
"This step is in line with the general Russophobic-policy of the conservative government aimed to demonize our country," Zakharova added.
She said the refusal of the British authorities to interact with Russia in investigating the Salisbury incident, to grant Russia access to the victims, as well as its reluctance to disclose to Russia of documents necessary for an objective investigation, presents "proof" of London's intentions.
Skripal, a former Russian spy, and his daughter were poisoned on March 4 in the southern English city of Salisbury. Britain accused Russia of being "highly likely" to have used a military-grade nerve substance for the poisoning, quoting an investigation carried out by British experts.
Following the incident, Britain expelled a number of Russian diplomats. The United States and a number of European states supported London by also expelling Russian diplomats from their countries. Russia expelled an equal number of foreign diplomats in response.
Experts from the Organization for the Prohibition of Chemical Weapons (OPCW) confirmed the findings of their British colleagues after carrying out an independent investigation.
Moscow, however, denied any involvement and refused to accept the OPCW conclusions until they were given access to the investigation, its officials said.
Zakharova said that Russia is still ready for constructive engagement with Britain to clarify the incident "in any international legal format."
"And we urge London not to hurry to destroy the evidence," she said.