The justice department appears to have prepared an indictment against WikiLeaks founder Julian Assange, according to secret charges that were accidentally revealed in an unrelated court filing, reports The Washington Post. The disclosure was made by Assistant US Attorney Kellen S. Dwyer, who is also assigned to the WikiLeaks case, according to The Post.

It is unclear how exactly the Assange reference ended up in the unrelated filing, but The New York Times speculates that prosecutors had pasted text from a similar court filing into the wrong document. Legal analysts cited by The Guardian agreed, and said that it’s not uncommon for prosecutors to copy text from past documents before changing names and other details for a new filing. Sources speaking to The Post described the references to Assange as true, but unintentional.

You guys should read EDVA court filings more, cheaper than a Journal subscription pic.twitter.com/YULeeQphmd — Seamus Hughes (@SeamusHughes) November 16, 2018

Hours before the inadvertent disclosure was discovered by Seamus Hughes on Twitter, the Wall Street Journal reported that the Justice Department is preparing to prosecute Assange, and is “optimistic” that it will be able to successfully extradite him to face trial in the US. It is not yet clear what Assange would be charged with. Investigations into Assange have been ongoing since WikiLeaks first published thousands of classified US government documents in 2010. More recently, an indictment from the Mueller investigation portrayed WikiLeaks as a tool for Russian intelligence to release hacked Democratic emails during the 2016 presidential election.

The WikiLeaks founder has been living in London’s Ecuadorian embassy since 2010, where British authorities have been unable to arrest him. Initially, this was an attempt to avoid extradition to Sweden in relation to a sexual assault case, which Assange has always maintained was a pretext for extradition to the US. Sweden has since dropped the case, but there’s still a warrant for his arrest. Ecuador initially said it wouldn’t hand him over to any country with the death penalty. The country’s relationship with Assange has deteriorated since last year’s election of a new president, however, who says Assange’s presence in the embassy is unsustainable.