Politicians in the US escalated an investigation into Apple, Amazon, Facebook and Google, asking the companies to hand over internal information covering a variety of competition-related matters.

The House of Representatives’ Judiciary Committee, which oversees federal courts and policing, requested the companies provide executive communications about acquisitions, advertising policies, search algorithms, and data use, as part of an investigation begun in July.

Committee member Doug Collins stated the information will help politicians evaluate whether anticompetitive activity is occurring and if laws need to be updated to “better promote competition in the digital markets”.

Under scrutiny are Facebook’s purchase of Instagram, WhatsApp and analytics company Onavo; and Google’s acquisitions of YouTube, and advertising services DoubleClick and AdMob.

Apple and Google were also pressed to reveal information about their app policies, while all four companies were also asked to provide documents related to any other competition investigations against them.

The quartet are reportedly part of a Department of Justice investigation; Google and Facebook are being probed by state legal officials; with Facebook also under scrutiny by the Federal Trade Commission.