Search engine giant Google is under investigation by American regulators over whether it manipulates results to block competitors and promote its own services. Through its powerful search engine, Google handles two-thirds of all web searches in the US. Now the web giant is under investigation by the US Federal Trade Commission (FTC) over whether it is abusing that market dominance. Competitors have long complained that rather than giving users the best results, the widely used search engine promotes Google's own services, like map and travel websites, at their expense.