Barry Pollack, WikiLeaks founder Julian Assange’s Washington, D.C.-based attorney, has left Miller & Chevalier for a smaller boutique law firm and is representing an unnamed client involved in special counsel Robert Mueller’s Russia probe.

“I am representing someone with respect to the Mueller probe,” said Pollack, who is now a partner at Robbins, Russell, Englert, Orseck, Untereiner & Sauber. “The representation is not public at this point,” he said.