Dwyer later wrote that the charges would "need to remain sealed until Assange is arrested". Dwyer is also probing WikiLeaks. People familiar with the matter said what Dwyer was disclosing was true, but unintentional.
"The court filing was made in error", said a spokesperson for the USA attorney's office Joshua Stueve. "That was not the intended name for this filing", the spokesman, Joshua Stueve, said in an email.
Wikileaks founder Julian Assange has been charged by U.S authorities, according to reports. Investigators also had explored whether WikiLeaks could face criminal liability for the more recent revelation of sensitive Central Intelligence Agency cyber-tools.
One of the indictments referred to WikiLeaks, described as "Organization 1", as the platform the Russians used to release the stolen emails.
A spokesman for the special counsel's office declined to comment. It is unclear what charges Assange faces.
The Wall Street Journal reported earlier on Thursday that Justice Department officials were preparing to prosecute Assange. Many traditional outlets routinely publicize government secrets.
Prosecuting someone for publishing truthful information would set a awful and risky precedent. It was submitted to the federal court in the eastern district of Virginia, which handles many cases involving national security. Seitu Sulayman Kokayi, 29, was charged with enticing a 15-year-old girl to have sex with him and send him pornographic images of herself.
The filing carried markings indicating it was originally filed in a US District Court in Alexandria, Virginia in August.
U.S. media were alerted late Thursday to the inadvertent disclosure, thanks to a tweet from Seamus Hughes, deputy director of the Program on Extremism at George Washington University.
Pollack said he did not know if Assange has been charged.
Facing extradition from Britain to Sweden to be questioned in a sexual molestation case, Assange six years ago took refuge in Ecuador's London embassy, where initially he was treated as a welcome guest. The sex offence charges against Assange have eventually been dropped but the whistleblower has not left the diplomatic mission, where he was granted asylum, over fears that he might be seized by the UK authorities and extradited to the United States where he is wanted for leaking classified documents.
It remains unclear both if and how Assange could face charges in the USA state, Currently, he resides under political asylum inside the Ecuadorian Embassy in Knightsbridge, London.