Assange, a 39-year-old Australian, went into hiding last week as his controversial Web site posted more than 250,000 U.S. diplomatic documents and Interpol issued an international arrest warrant for him on sexual abuse charges.
Lawyer Mark Stephens told the BBC his client, a self-professed former Internet hacker, was a journalist who was being targeted for publishing material he didn't write.
"He received, unbidden, an electronic brown envelope that journalists receive," Stephens said. "This particular journalist has put it out. What they are doing is criminalizing him, criminalizing journalistic activity."
In a rare public disclosure in November, Assange denied the sexual assault allegations and said the activities were consensual.
His lawyer said there was good reason for Assange to be hiding, the British network reported Sunday.
"We've seen a number of suggestions that he should be assassinated, again from credible sources around the world," Stephens said.