MOSCOW, may 4. /TASS/. Moscow doubts the data of the Director General of the Organization for the prohibition of chemical weapons (OPCW) Ahmet üzümcü on the quantity of the substance used to poison ex-GRU Colonel Sergei Skripal and his daughter Julia in English Salisbury. This was at the briefing on Friday, said the official representative of the Russian foreign Ministry Maria Zakharova.