MOSCOW, April 5. /TASS/. Moscow has questions on whether the activities of Britain’s Porton Down laboratory are in conformity with the Chemical Weapons Convention (CWC), Russian Foreign Minister Sergey Lavrov said on Thursday.

"We have taken note of a statement made by Porton Down’s director that the laboratory had drawn no conclusions on where this substance (allegedly used to poison the Skripals) had been made and could not do so, they (just) determined the chemical composition of that substance," Lavrov stated. "The question of whether this laboratory has a counterpart remains open."

"This laboratory leaves one asking questions on whether its existence and activities are in conformity with [Britain’s] compliance with its obligations under the Chemical Weapons Convention," the minister noted. "Nevertheless, as an honest professional and chemist, (the laboratory’s head) said Porton Down had never identified that this substance had originated in Russia or anywhere else."

According to Lavrov, after that the UK Foreign Office, which earlier claimed that Porton Down had confirmed the Russian origin of that substance immediately began deleting its prior tweets on the subject.