Risen Banned in Australia

Kotaku Australia brings word that Piranha Bytes' Risen has been refused classification in Australia because they found that the game contained "sexual activity and drug use related to incentives or rewards." Here's what the ESRB has to say about the game, which might help us understand their reasoning:
During the course of the game, players can interact with prostitutes (referred to as (whores) in the game) at a local brothel. Players can trigger a lengthy dialogue to engage in their services; sexual activity is strongly implied, but never depicted on screen. Many of the characters in the game smoke a fictional drug called (brugleweed.) The (wood reefer) plant is described as having a mild relaxing effect on users, and can be bought, sold, and used by players. Some profanity (e.g., (f*ck) and (sh*t)) can be heard in the dialogue.
And then Kotaku goes on to provide a couple of updates:
UPDATE: To clarify, the quoted extract is from the US ratings board description of the game. It simply details elements from the game that the ESRB noted could affect its rating. It should not be taken as a list of reasons why the game was banned in Australia.

UPDATE#2: A spokesperson for Risen's Australian distributor Madman Interactive has told us that the Classification Board felt that the game contained (sexual activity and drug use related to incentives or rewards.) That's an instant ban right there. Madman are considering all their options but have yet to decide whether they will appeal the decision or seek to edit the game to suit an MA15+ rating.