A lawyer for Julian Assange, the founder of the WikiLeaks website, said on Friday she expects US prosecutors will indict her client soon for espionage.

The lawyer, Jennifer Robinson, told ABC News in London that a US indictment of Assange was imminent but the report offered no further details or comment by Robinson about why she believed charges were likely to be filed soon.

The US Justice Department has been looking into a range of criminal charges, including violations of the 1917 Espionage Act, that could be filed in the WikiLeaks case involving the release of hundreds of confidential and classified US diplomatic cables.

A Justice Department spokeswoman declined to comment on Robinson's prediction of an indictment.

US Attorney General Eric Holder earlier this week said that prosecutors were looking beyond the espionage law for possible charges.

"That is certainly something that might play a role, but there are other statutes, other tools at our disposal," Holder told reporters on Monday. "I authorized just last week a number of things to be done so that we can get to the bottom of this and hold people accountable."