Update: Though the free "Prey in the Darkness" downloadable content for Batman: Arkham Aslyum is already available on Xbox 360 in Europe, Eidos has clarified that the tomorrow's North American release of the add-on will be a PlayStation 3 exclusive.

"The new content will be available beginning September 24th in North America as a free download exclusively on the PlayStation Network," the company explained in a joint statement with Warner Bros. "Outside of North America, the Prey in the Darkness Map Pack will be available on both PlayStation Network and Xbox LIVE Marketplace."

Original: Eidos today announced the "Prey in the Darkness Map Pack" for Batman: Arkham Asylum, another dose of two challenge maps to the popular Bat-game.

The DLC includes the "Heart of Darkness FreeFlow Combat" map, in which "players will battle a mob of relentless and maniacal enemies at the Arkham Pumping Station." The "Hothouse Prey Invisible Predator" map will challenge players to "effectively take down enemies at the Abandoned Glasshouse."

The maps are free and due to arrive tomorrow on Xbox 360 and PlayStation 3 in the UK. (Update: They're already available in Britain's Xbox Live Marketplace.)

Eidos made no mention of a PC release and we've yet to receive details on a North American release for the DLC. Like Batman, we will thoroughly investigate this discrepancy, most likely with X-ray vision.