Rupert Murdoch’s News International has been hit by hackers after his UK newspapers The Sun and The Times revealed the arrest of a UK hacker who had been linked with the international hacking group LulzSec.

The attack, which was in retaliation for coverage of the arrest of Ryan Cleary, at one stage slowed access to the websites of the Sun and The Times,  after servers owned by News International, who also publish the Australian and Daily Telegragh in Australia, were bombarded with internet traffic in an attempt to make them crash.

The international hacking group LulzSec, of which police suspect Mr Cleary to be a member, has taken exception to the Sun’s coverage of the case since he was held on Monday.

LulzSec has also threatened a major attack on government websites today, using the Twitter website to promise a “major leak”.

News International has declined to comment on the attacks on its servers, but a source told The Daily Telegraph in the UK, that computers in Russia had been used to attack the Sun website and Times newspaper in the early hours of yesterday.

The production of The Times was not affected and the website of the Sun – described by LulzSec as the worst “UK publication in existence” – was slowed down but did not crash at any time.