Some 1.7 to 3 million Steam codes for a free copy of Codemasters' DiRT 3 have been leaked onto the web, according to reports. The codes were meant to be distributed with specific Radeon cards and redeemed at AMD4u, as part of a promotion by the game's publisher and AMD. But apparently hackers made off with the codes via a .htaccess exploit on the graphics firm's server and released them onto various forums.

The exact number of codes leaked is as-of-yet unknown, but Codemasters says it is already working on blocking those codes now to prevent them from being used. The codes should be easy to track down via Steam. It's unclear if users would simply lose access to the game or see their accounts being blocked. Though the latter seems unlikely, your best bet is to skip on any eye catching deals for DiRT 3 Steam codes on eBay and the like for a while.

As Gamasutra notes, this is the second major hacking incident that Codemasters has had to deal with in just a few months. In June, the studio announced that hackers had broken into its site and gained access to its members' personal information, including thousands of registered CodeM and forum users' names, email addresses, phone numbers, dates of birth, passwords, IP addresses and Xbox gamer tags – - though personal payment details were not stored or at risk.

Update: AMD has sent us the following statement regarding the hack:

"This past weekend, activation keys associated with free Dirt 3 game vouchers shipping with select AMD products were compromised.  These activation keys were hosted on a third-party fulfillment agency website, www.AMD4u.com, and did not reside on AMD's website.  Neither the AMD nor Codemasters servers were involved.

We are working closely with Steam, Codemasters, and our fulfillment agency, to address the situation. AMD will continue to honor all valid game vouchers, however the current situation may result in a short delay before the vouchers can be redeemed."

Update 2 (Sep. 14): The Dirt 3 redemption site is now fully operational again.

"AMD is pleased to announce that, having worked closely with Steam, Codemasters, and their fulfillment agency, AMD has now addressed the situation with Dirt3 game vouchers and the Dirt3 redemption page is now fully operational. Consumers are now able to input their existing codes for redemption of all valid vouchers."