PRAGUE (Reuters) - The Czech Foreign Ministry has summoned Russia’s ambassador over Moscow’s claims that the nerve toxin used against a former Russian double agent and his daughter in southern England came from the Czech Republic.

“The Russian Federation’s ambassador has been summoned for tomorrow morning (Wednesday) to the ministry to explain the Russian side’s false claim that the Novichok substance used in the Salisbury attack might have originated in the Czech Republic,” the ministry said on its official Twitter account.

On Saturday, Foreign Minister Martin Stropnicky denied the claim.

Britain accuses Moscow of using the Soviet-era military-grade nerve agent Novichok in an attack on former spy Sergei Skripal and his daughter, who are critically ill in hospital, a charge which Russia has denied.