News International websites for the Times and the Sun were taken down last night after hackers targeted the Sun's web pages and redirected traffic to another page falsely reporting that Rupert Murdoch had been found dead.

The LulzSec hacking collective hacked the tabloid's site, and also claimed to be "sitting on their [the Sun's] emails" and that they would release the emails on Tuesday. They tweeted what they claimed was Rebekah Brooks's email address, and said they knew her password combination.

The breach was apparently the first hack of a major UK newspaper's website.

News International's corporate web page also appeared to have been disabled after News International technicians took down pages for the Times such as thetimes.co.uk as a precautionary measure.

LulzSec has previously targeted companies including Nintendo. It put up the fake Sun web page after finding a way into the News International system and changing the code for the breaking news banner on the Sun's site. When the Sun page refreshed, readers were redirected to a fake page on the New Times site at new-times.co.uk/sun.

The hoax story suggested Murdoch had taken [the rare-earth metal] "palladium" before "stumbling into his famous topiary garden late last night". The page later redirected to LulzSec's Twitter account.

"This is only the beginning. Fuck you Murdoch. You are next," tweeted the person behind the LulzSec Twitter account, thought to be the member known as Topiary, a Swedish-born citizen who lives in the Netherlands. A News International spokeswoman confirmed the company was "aware" of what was happening, but made no further comment.

The episode demonstrated that News International's systems have been vulnerable to hackers for some time. Rumours had surfaced that the hacking collective Anonymous would hit the site last week, but nothing appeared to come of it.

• This article was amended on 19 July 2011. The original said that the hoax story suggested Murdoch had taken the radioactive poison palladium. This has been corrected.