Ukraine's interior minister said on Tuesday a suspect in the Skripal poisoning case, working for Russian military intelligence, had been identified in Ukraine as a man who helped the former Ukrainian president flee to Russia in 2014.

It was not immediately clear whether minister Arsen Avakov was citing information from Ukrainian intelligence or quoting the accounts of journalists. He released a statement following a meeting with a British minister.

His spokesman declined to comment further. A lawyer for former President Viktor Yanukovich, who escaped to Russia in February 2014 during a wave of street protests, has previously denied that the Skripal suspect had helped Yanukovich.

Former Russian double agent Sergei Skripal and his daughter Yulia were found slumped on a public bench in the English city of Salisbury in March. Britain says they were poisoned with a nerve agent administered by Russian intelligence officers.