Vladimir Putin said Russia has identified the two men wanted by British authorities for the Salisbury poisoning and called on them to speak to the media.

One of them appeared to promise an interview to a Russian state news outlet next week, but doubts remain whether he is the same man sought by the UK police.

Two Russians known as Alexander Petrov and Ruslan Boshirov have been charged with attempting to murder of former Russian spy Sergei Skripal and his daughter Yulia in Salisbury in March by spraying Novichok nerve agent on the handle of their door. The metropolitan police have said these names are probably aliases.

Theresa May's spokesman on Wednesday reiterated that “these men are officers of the Russian military intelligence service the GRU who used a devastatingly toxic chemical weapon in Salisbury.”

Asked about the case on Wednesday at the eastern economic forum in Vladivostok, Mr Putin tried to shift the blame away from the Russian state, insisting that the two men were “civilians”.

“We know who they are, we found them,” he said at a panel with the leaders of China and Japan. “I hope they will appear on their own to talk about themselves, that will be better for everyone. There's nothing especially criminal there, I assure you.”