A new court document signed by a federal judge in Washington has confirmed that the U.S. government hired Carnegie Mellon University researchers to hack into the Tor encryption service in 2014.

Back in November, the Tor Project, which maintains and develops Tor, accused the Carnegie Mellon University (CMU) of attacking Tor. It strongly believed that researchers at CMU's Software Engineering Institute were behind the attack.

CMU then pushed out a press release that suggested it denied helping the FBI hack Tor for $1 million.

"In the course of its work, the university from time to time is served with subpoenas requesting information about research it has performed," read CMU's media statement. "The university abides by the rule of law, complies with lawfully issued subpoenas and receives no funding for its compliance."

CMU, though, does not directly address whether it hacked the Tor network as allegedly ordered by the FBI to uncover the identities of the people behind Silk Road 2.0. Brian Farrell, reportedly among the top administrators of dark Web marketplace Silk Road 2.0, was arrested more than a year ago. Farrell is charged with conspiracy to distribute heroin, cocaine and methamphetamine through the portal.

In a blog post the Tor Project published in November, it says that the researchers from the CMU "were paid by the FBI to attack hidden services users in a broad sweep, and then sift through their data to find people whom they could accuse of crimes."

Now, the existence of a subpoena plus the name of the university have been confirmed via a court order signed by U.S. District Judge Richard Jones.

Some of the details that the Tor Project included in its post, though, appear to be inaccurate. For instance, the research was not funded by the FBI, but rather the Department of Defense, according to the court document.

This court order was released in response to Farrell's Motion to Compel Discovery.

When asked for comments regarding the court order, CMU's spokesperson Kenneth Walters told Vice Motherboard in an email that the university "has nothing to add" beyond its media statement it released on Nov. 18.

Here is the full copy of the "Order On Defendant's Motion To Compel," if you wish to know more about the case.