Federal prosecutors are conducting a criminal investigation into controversial deals Facebook struck to share its users' data with dozens of tech companies without the users' knowledge, The New York Times reported Wednesday.

A New York grand jury has subpoenaed records from two smartphone makers involved in the partnerships, anonymous sources described as familiar with the requests told the Times. Data shared without users' knowledge included friends' names, genders and birth dates.

Facebook admitted in June that it provided dozens of tech companies with special access to user data after publicly saying it restricted such access in 2015. However, Facebook continued sharing information with 61 hardware and software makers after it said it discontinued the practice in May 2015, it said in June.

The social network's arrangements allowed Netflix and Spotify to read Facebook users' private messages, the Times reported, citing internal documents. Other arrangements allowed Amazon to obtain users' names and contact information through their friends and permitted Yahoo to view streams of friends' posts as recently as this summer, the Times reported, despite Facebook's statements that it had ended that type of data sharing.

The social network has been under scrutiny since the revelation in March that consultancy Cambridge Analytica had misused Facebook user data in the run-up to the 2016 US presidential election. Since then, Facebook CEO Mark Zuckerberg has testified in front of Congress and the European Parliament to answer questions about Facebook's handling of user data.

Facebook's disclosure was included in 747 pages of documents given to Congress in response to hundreds of questions about data privacy posed to Zuckerberg by members of Congress about Cambridge Analytica, which  improperly accessed personal information on up to 87 million Facebook users. That revelation prompted a backlash that raised questions about whether Facebook can be trusted to protect the personal information of its 2 billion users.

It wasn't immediately clear what the grand jury was focused on or when its investigation began. The US Attorney's Office for the Eastern District of New York declined to confirm or deny the investigation's existence.

Facebook responded by noting that other federal investigations are reportedly underway.

"We are cooperating with investigators and take those probes seriously," a Facebook spokesperson said in a statement. "We've provided public testimony, answered questions, and pledged that we will continue to do so."

News of the controversial agreements emerged in June when the Times reported that Facebook had agreed to provide access to large amounts of user data to at least 60 different device makers -- including companies like Apple, Microsoft, Samsung and BlackBerry.

Facebook said in June it granted a special "one-time" six-month extension to companies that ranged from AOL to package-delivery service United Parcel Service to dating app Hinge so they could come into compliance with the social network's new privacy policy and create their own versions of Facebook for their devices.

The Justice Department didn't immediately respond to a request for comment.

CNET's Queenie Wong contributed to this report.