NY Times article
In addition, Zynga’s $520 million in financing includes a recent infusion of $300 million through two, roughly equal investments from Softbank and Google, according to people briefed on the investments who spoke on condition of anonymity because they were not authorized to discuss Zynga’s finances publicly. Google and Zynga are also in the early stages of exploring a collaboration, these people said. Zynga and Google declined to comment or confirm a Google investment.
-Will Zynga Become the Google of Games? - NYTimes.com