File Photo (Xinhua)

WASHINGTON, Nov. 15 (Xinhua) -- A U.S. attorney mistakenly revealed that WikiLeaks founder Julian Assange had been charged, according to a court filing made public Thursday.

In a court filing that was unrelated to Assange, Assistant U.S. Attorney Kellen Dwyer wrote "due to the sophistication of the defendant and the publicity surrounding the case, no other procedure is likely to keep confidential the fact that Assange has been charged."

Dwyer later wrote that the charges "need to remain sealed until Assange is arrested."

Joshua Stueve, a spokesman for the U.S. attorney's office in the Eastern District of Virginia, said: "the court filing was made in error. That was not the intended name for this filing."

U.S. media cited sources familiar with the matter as saying that Dwyer, who was assigned to the WikiLeaks case, unintentionally revealed the information, which itself was accurate.

The court filing was originally put on social media by Seamus Hughes, an expert on terrorism at the George Washington University.

Assange released a batch of U.S. classified information in 2010 through his website WikiLeaks. He has resided in the Ecuadorian embassy in London since 2012 to avoid arrest.