Former oil tycoon Mikhail Khodorkovsky, a fierce critic of Russian President Vladimir Putin, says he is considering applying for political asylum in the UK and feels safe in London, BBC News reports.

He was speaking in a BBC interview after a Russian court declared him "under arrest in absentia" over the 1990s murder of a Siberian mayor.

"Definitely I'm considering asking for asylum in the UK," he said. Putin "sees me - it's obvious now - as a serious threat", he said.

Once Russia's richest man, the former head of the now defunct Yukos oil firm spent 10 years in a Siberian prison on fraud charges, which he says were politically motivated.

Putin pardoned him in 2013 and he now lives abroad, mainly in Switzerland.

"I'm considered by President Putin as a threat, economically, because of the possible seizure of Russian assets abroad, and politically, as someone who will potentially help democratic candidates in the coming 2016 elections," he said.

Russia will hold elections to the lower house of parliament - the State Duma - next year. The Duma is currently dominated by Putin's supporters.