Federal prosecutors in New York are pursuing a criminal investigation into data deals between Facebook and other large technology companies, according to a person familiar with the matter.

The probe is part of a range of inquiries by US authorities in the aftermath of the Cambridge Analytica scandal last year, when the UK data company was accused of improperly accessing Facebook user data, and the subsequent disclosure by Facebook of additional data-sharing deals with smartphone makers and other businesses.

The investigation in the eastern district of New York was first reported by The New York Times, which said two unnamed companies who had arrangements with Facebook had received grand jury subpoenas.

Last year, Facebook confirmed it was co-operating with investigations by the Department of Justice and Securities and Exchange Commission resulting from the Cambridge Analytica revelations, in addition to a Federal Trade Commission probe into whether the affair violated a 2011 consent decree.

It is unclear how the investigation in the eastern district of New York relates to those previously disclosed investigations and what possible case prosecutors there are pursuing.

“It has already been reported that there are ongoing federal investigations, including by the Department of Justice,” said a Facebook spokesperson. “We are co-operating with investigators and take those probes seriously. We’ve provided public testimony, answered questions, and pledged that we will continue to do so.”

The justice department and the Brooklyn US attorney’s office declined to comment.

The investigation comes as the company was hit by the severe technical difficulties, leading to one of the longest outages on the social network and its photo-sharing platform Instagram in years. “We’re aware that some people are currently having trouble accessing the Facebook family of apps,” a Facebook spokesperson said.

The latest criminal probe adds to the mounting legal and political questions surrounding Facebook, which is facing questions about its data practices, size and influence.

In the US, Democratic politicians have begun to talk about breaking up large Silicon Valley companies such as Facebook and Amazon, with presidential contender Elizabeth Warren vowing to force Mark Zuckerberg to spin-off Instagram and WhatsApp, the messaging platofrm, if she is elected.

Last week, Mr Zuckerberg announced a plan to allow users of Facebook, Instagram and WhatsApp to message each other securely, a move that would more closely bind the three businesses and mark a shift away from the public sharing philosophy that has defined the social network he founded.