A PUBLIC inquiry into the assassination of Russian dissident Alexander Litvinenko has found that there is a "strong circumstantial case" that the Russian state killed him — and President Vladimir Putin "probably" approved it.

In his report, published yesterday, inquiry chairman Sir Robert Owen said it was likely the Russian leader signed off on the poisoning of the former KGB agent in London in 2006 after he repeatedly criticised the Kremlin in public.

Andrei Lugovoi and Dmitri Kovtun, who are strongly suspected of carrying out the assassination, were probably being directed by Moscow’s FSB intelligence service when they poisoned the 43-year-old with radioactive polonium 210 at a Mayfair hotel, the report found.

In addition to Mr Putin, Mr Owen also singled out then FSB head Nikolai Patrushev.

He pointed to Mr Litvinenko’s work for British intelligence, criticism of the FSB and Mr Putin, along with his association with other dissidents such as Boris Berezovsky, as likely motives for the murder.

The report also said the deceased made "repeated highly personal attacks" on the president after seeking asylum in Britain in 2000, including an allegation of paedophilia in July 2006.

"I am satisfied that in general terms, members of the Putin administration, including the president himself and the FSB, had motives for taking action against Litvinenko, including killing him, in late 2006," Mr Owen wrote.

Although the evidence was "circumstantial," other cases suggested that "in the years prior to Litvinenko’s death the Russian state may have been involved in the assassination of Mr Putin’s critics."

An earlier attempt was made to poison Mr Litvinenko, also using polonium 210, a fortnight before he ingested the fatal dose, the report found.

Speaking to the Interfax news agency, Mr Lugovoi, now a Russian MP, said: "The results of the investigation that were announced today once again confirm London’s anti-Russian position and the blinkered view and unwillingness of the British to establish the true cause of Litvinenko’s death."

Home Secretary Theresa May, who had opposed the establishment of an inquiry, described the "state-sponsored" assassination as a "blatant and unacceptable" breach of international law.

Amnesty International’s Europe programme director John Dalhueisen said the killing would "remain a case of justice half done" if the British government failed to put pressure on Russia to open an investigation.