Hills was appointed as Rock You's general manager for Asia-Pacific in April this year following his resignation as regional CEO of Group M Search in January.
Based in Singapore, Hills was responsible for overseeing the California-based company's operations across the region in markets including Singapore, Hong Kong, Australia, India and Malaysia.
He came onboard to help grow the company by linking with advertisers and brands to develop application-based social networking initiatives including advertisements and fan pages.
Industry sources have confirmed this news, with some saying that Hills was made redundant.
Both Rock You and its PR affiliate Access PR declined to comment.
Rock You has recently been in news for laying off a significant number of employees in non-gaming divisions as part of an aggressive effort to develop its social gaming business.
Although the social networks applications business will pursue advertising, it will be predominantly in the social games arena.