Facebook has suspended a US-based analytics firm while it investigates concerns about the collection and sharing of user data.
Crimson Hexagon, based in Boston, describes itself as offering “consumer insights” and has contracts with government agencies around the world.
Facebook said it was looking into whether some of these deals were in violation of its policies on surveillance.
The network said it had not found any evidence so far that data had been improperly obtained.
According to the Wall Street Journal, Crimson Hexagon has "contracts to analyse public Facebook data for clients including a Russian nonprofit with ties to the Kremlin and multiple US government agencies”.
In March 2017, Facebook prohibited user data being used for government surveillance following pressure from civil liberties groups concerned about the targeting of dissidents and protesters.
"We don't allow developers to build surveillance tools using information from Facebook or Instagram,” a Facebook spokesman said in a statement on Friday.
"We take these allegations seriously, and we have suspended these apps while we investigate.”
Crimson Hexagon works with a data set that includes, according to its own website, more than one trillion social media posts take from Facebook, Instagram, Twitter and others. It boasts of being able to analyse more than 160m photographs posted online every day.
As well as government work, Crimson Hexagon has had deals with commercial companies including Adidas, Samsung and the BBC.
Gathering and sharing “data insights” with businesses is not against Facebook’s policies.
"People can share their information with developers on Facebook and Instagram - just as they can when they download an app on their phone,” said Ime Archibong, Facebook’s head of partnerships.
He said developers were allowed to "use public or aggregated information to produce anonymised insights for business purpose”.
Where Crimson Hexagon would fall foul of Facebook’s rules is if the data was used to create tools for surveillance, though Facebook has never clarified how its policy works in practice.
Crimson Hexagon did not respond to requests for comment from the BBC. In a blog entry posted by the firm on Friday, its chief technology officer Chris Bingham defended the company’s work - without specifically mentioning Facebook’s investigation.
"Crimson Hexagon only collects publicly available social media data that anyone can access,” he wrote, seeking to distance his firm from Cambridge Analytica, the firm which allegedly used an app to scrape private data from the network.
Mr Bingham added: "The real conversation is not about a particular social media analytics provider, or even a particular social network like Facebook. It is about the broader role and use of public online data in the modern world.”
A spokesman for Facebook told the BBC the firm had already spoken with Crimson Hexagon, and the firms are due to meet in the coming days.