CHONGQING, China — Wang Lijun reveled in his image as the consummate crime fighter. An ethnic Mongolian policeman with a fondness for expensive overcoats, he directed crackdowns on organized crime, performed autopsies, patented designs for police uniforms and was even named an honorary professor at the institute of a famous American forensic scientist. His earlier exploits inspired a television series. All that was missing was a mask and cape.

His coup de grâce was revealing to American diplomats in February his suspicions that the wife of Bo Xilai, his boss who was then running this western metropolis, had murdered a British business associate.

But there is another side to Mr. Wang, now accused by many people of being as much a criminal as those he boasted of persecuting. He locked up and tortured lawyers, business executives and other police officers as part of a relentless crackdown he oversaw, say those victims and people in Chongqing with police contacts.

In April, a senior official in Chongqing signaled at an internal police meeting the start of a wide inquiry into the allegations. Mr. Wang also ran an extensive wiretapping campaign. And he helped cover up the killing last November of the British businessman, Neil Heywood, said two people with ties to the police.