Russia's embassy in London said on Sunday its website crashed in a suspected hacking attack just before Prime Minister David Cameron begins the first visit by a British leader to Moscow since the 2006 killing in London of a Kremlin critic.

The embassy said it had set up a mirror website ( to meet the increased interest of the public and media for information before Cameron flies to Russia on Sunday.

Prior to the visit of Prime Minister David Cameron to Russia, the website of the Russian Embassy in London ( was brought down by a suspected DDoS (distributed denial of service) attack, the embassy said in a statement.

A DDoS attack is one in which hackers flood a website with requests for information, making it unavailable to legitimate users.

Britain's relations with Russia have been soured by a dispute over the 2006 murder in London of Kremlin critic Alexander Litvinenko, a former Russian spy who died from poisoning by radioactive polonium-210.

Russia has refused to extradite Andrei Lugovoy, an ex-KGB bodyguard Britain wants to prosecute for Litvinenko's murder. That sent ties between the countries plunging to a post-Cold War low and led to tit-for-tat diplomatic expulsions.

Relations have improved slightly since Cameron took power in Britain last year at the head of a coalition government and since Dmitry Medvedev became Russian president in 2008.

A Russian embassy spokesman said problems with the website began on Friday night. The site was accessible for some time on Saturday but was down again on Sunday, he said.

The website carries articles by Russian Foreign Minister Sergei Lavrov and by Alexander Yakovenko, Russia's ambassador to London, on Cameron's 24-hour visit.

(Reporting by Adrian Croft; Editing by Janet Lawrence)