A global chemical watchdog group has confirmed Germany and other countries’ findings that Russian opposition figure Alexei Navalny was the victim of an attack with a Soviet-era nerve agent.

German Chancellor Angela Merkel’s spokesman Steffen Seibert said in a statement that the Organisation for the Prohibition of Chemical Weapons (OPCW) carried out its own analysis of samples taken from Mr Navalny, and they “agree with the results already from special laboratories in Germany, Sweden and France”.

“This once again confirms unequivocally that Alexei Navalny was the victim of an attack with a chemical nerve agent from the Novichok group,” Mr Seibert said.

He renewed Germany’s call on Russia to fully investigate and explain what happened to Mr Navalny, who fell ill on a domestic flight in Russia and was later taken to Berlin for treatment.

Mr Seibert said Germany received the OPCW’s report on Monday and was still examining it.

Officials were still trying to determine how much of the information could be released to the public without causing a security risk by allowing knowledge of the substance to “fall into the wrong hands”.

He added that Germany would be consulting closely in coming days with the OPCW and a group of European Union partners to talk about the next steps.

“Any use of chemical weapons is serious and cannot be without consequences,” Mr Seibert said.