LONDON (Reuters) - British Prime Minister Theresa May’s spokesman said on Monday the government could not comment on why Russian billionaire Roman Abramovich’s visa was yet to be renewed.

Abramovich, best known in Britain as the owner of Premier League soccer club Chelsea, is in the process of renewing his visa as part of a standard procedure after it expired last month but it is taking longer than usual, sources told Reuters on Sunday.

Relations between Moscow and London have been strained since the poisoning former Russian double-agent Sergei Skripal in Britain in March, an act Britain has blamed on Russia but in which the Kremlin denies any involvement.