Peter Thiel’s AI company Palantir, whose clients have included the CIA and US immigration agency ICE, is back in the spotlight for all the wrong reasons. A new report claims a glitch in its secretive software program used by the FBI allowed unauthorized personnel to access private data for more than a year. According to The New York Post, the mishap was revealed in a letter by prosecutors in the Manhattan federal court case against accused hacker Virgil Griffith. Palantir denied the claims in a statement and said the fault was caused by the FBI’s incorrect use of the software.

Griffith was arrested in 2019 for allegedly providing North Korea with information on how cryptocurrency and blockchain tech could help it to evade US sanctions. The incident in question revolves around the alleged hacker’s social media data, obtained through a federal search warrant in March 2020. According to the letter, the Twitter and Facebook information was uploaded to Palantir’s program through the default settings, effectively allowing unauthorized FBI employees to access it

Between May 2020 to August 2021, the material was accessed four times by three analysts and an agent. The FBI case agent assigned to Griffith’s case was alerted to the issue by a colleague earlier this month, according to the letter. Those who accessed the info reportedly told prosecutors that they did not recall using it in their investigations.

“An FBI analyst, in the course of conducting a separate investigation, had identified communications between the defendant and the subject of that other investigation by means of searches on the Platform that accessed the Search Warrant Returns,” the letter noted.

Palantir is trying to distance itself from the issue. “There was no glitch in the software,” it told The New York Post in a statement, adding that the “customer” did not follow the “rigorous protocols established to protect search warrant returns.”

Amid increasing growth, the last thing Palantir needs is a major PR crisis involving flaws in its software. Since going public last fall, the company has seen its revenues surge, though it’s operational losses are also increasing. Palantir’s customers now span government agencies, tech stalwarts like IBMand even mining group Rio Tinto. Plus, it’s working with commercial space companies to manage a meta-constellation of 237 satellites.

Editor’s note: This post originally appeared on Engadget.