The 50 US state attorneys-general currently investigating Google are preparing to expand their anti-trust probe beyond the company’s advertising business and include its Search and Android businesses.

The development comes as politicians on both sides raise concerns over Silicon Valley’s growing economic and social reach.

The attorneys-general will process subpoenas known as civil investigative demands, or CIDs, to support the inquiries, but they may not be served imminently.

So far, the investigation has explicitly focused on Google’s advertising business.

Search is the heart of Google’s business, through which Google collects both advertising revenue and data.