Manchester Chief Constable Michael Todd, 50, was found dead in Snowdonia, about 240 miles northwest of London, Deputy Chief Constable Dave Whatton said. He had been missing since going out for a walk Monday during his day off.
Whatton said the body, which was found Tuesday afternoon, had not yet been formally identified but he believed it was Todd.
He said a coroner's inquest would investigate the cause of death and did not give any further details.
Todd was elected vice president of the Association of Chief Police Officers of England and Wales in 2006, according to a biography on his Web site.
The association gave him the task of looking into accusations that Britain allowed the CIA to use the country's airports to fly people to other countries without any extradition hearings, a clandestine procedure known as "extraordinary rendition."
Todd's investigation concluded last June that there was no evidence to back the claim.
But last month, Britain admitted one of its remote outposts in the Indian Ocean had twice been used by the United States as a refueling stop for the secret transfer of two suspects.
He and his wife had a daughter and twin sons.
Last Mod: 13 Mart 2008, 14:32