Eidos Interactive has revealed details of the upcoming DLC for Batman: Arkham Asylum.

According to the publisher, the first downloadable add-on will be released free of charge for all formats on September 17. It will be followed the Prey In The Dark pack on September 24, which is rumored to be a PS3 exclusive.

The first pack was confirmed as multi-platform when an Eidos spokesperson replied to a post on the official Batman forums. “I’m happy to inform you, it will arrive at the same time,” they wrote.

It has also been speculated that the content will be titled the Insane Night DLC Pack, which contains the Dem Bones Scarecrow Challenge and Crime Alley Challenge Map Packs.

Batman: Arkham Asylum was released for Xbox 360 and PS3 on August 28, with a PC version due on September 18. The title was handed a Guinness World Record for the ‘Most Critically Acclaimed Superhero Game Ever’.

Eidos is yet to comment on the speculation.