Batman's next film to be set in Arkham Asylum?

Rumours are circulating that the next Batman film will take place in Arkham Asylum, the notorious psychiatric hospital for supervillains.
The fan site Batman-On-Film has received multiple anonymous sources corroborating this rumour. Director/star/script writer Ben Affleck has previously said the coming movie would draw from multiple comics while telling an original story. If the rumour is true, Affleck may be drawing inspiration from the Grant Morrison-written masterpiece Arkham Asylum: A Serious House on Serious Earth and the popular Arkham Asylum video games.
The rumour gels well with another rumour that the coming film will be loaded with villains.
It is worth nothing, however, that Affleck said last month that he wasn't satisfied enough with his script yet to begin shooting. He is authoring the script with comic book writer Geoff Johns.
In the meantime, Affleck's Batman features in Suicide Squad, which is due out August 5.