The head of the global chemical-weapons watchdog has rejected Russian claims that traces of a second nerve agent were discovered in the English city where a former Russian spy and his daughter were poisoned last month.
Britain blames Russia for the March 4 poisoning of Sergei Skripal and his daughter, Yulia, in Salisbury, and says it was carried out by a Soviet-developed nerve agent known as Novichok. Moscow denies involvement.
Russian Foreign Minister Sergei Lavrov on April 14 said Moscow had received confidential information from a laboratory in Switzerland that analyzed samples from the site of the poisoning.
He said the analysis indicated that samples contained the substance BZ.
Citing a report from the lab dated March 27, Lavrov said the evidence suggested the nerve agent used could be in the arsenal of the United States, Britain, and other countries. He also said the Soviet Union and Russia had never developed the agent.
OPCW Director-General Ahmet Uzumcu told a meeting of the agency on April 18 that a BZ precursor "was contained in the control sample prepared by the OPCW lab in accordance with the existing quality-control procedures."
"It has nothing to do with the samples collected by the OPCW team in Salisbury," Uzumcu added.
The British representative to the OPCW, Peter Wilson, told the gathering that London continued to believe evidence points to Russia's involvement in the attempted assassination.
'We believe that only Russia had the technical means, operational experience, and motive to target the Skripals," he said.
In a summary of its report made public last week, The Hague-based OPCW said that its investigators had confirmed Britain’s analysis of the type of toxic chemical used in the poisoning, without naming the substance involved.