A lawyer for Australian Guantanamo Bay detainee David Hicks says he has learned that his client has had his conditions at the prison camp altered for no reason. Joshua Dratel understands Hicks is back in solitary confinement.Mr Dratel, a civilian lawyer, is in Adelaide to meet potential witnesses in the Australian's case and some of his client's supporters. He says there is no legitimate reason for keeping his client under those conditions. "They have not provided any explanation and certainly there is not any disciplinary or security interest involved," he said. "It's a mystery in terms of any specific reason but we think that it's part of the arbitrary and punitive nature of the way that they treat David." A decision is still pending on Hicks's application for British citizenship, which could potentially see him freed.