High profile UK games developer Codemasters has admitted that hackers broke into the company’s servers earlier this month and stole customer login data, including names, addresses and dates of birth.

According to an email sent to customers at the end of last week, the attack happened on 3 June, a week after the company had first reported that it was under attack. So severe has been the later attack that the company has had to close its website, redirecting visitors to its Facebook page.

Anyone using their Codemasters login password and or user name for other sites has been advised to change every instance to head off the possibility that hackers will use the stolen credentials to attack other commonly used sites. Users should also be on the lookout for unsolicited phone calls and emails, the company warned.

Stolen data is not said to include credit card details, which will be slim consolation to games subscribers already stung by Sony's historic April data breach disaster.

Questions about the chain of events that have left the company inaccessible remain to be cleared up. After the first attack, Codemasters said that the first attack had targeted admin logins but that passwords had been encrypted and were not usable to the attackers. The company put its website back online after a short period of downtime, a decision that now looks rather hasty.

Codemasters is best known for games such as the Colin McRae rally franchise and Lord of the Rings online multiplayer. The company is considered a pioneer of UK gaming, having been founded in 1986 by Richard and David Darling, both awarded CBE honours by the Queen in 2008 after selling its remaining stake in the company for £80 million ($130 million).