Little is known about the exact circumstances in which Wang Shuhua was killed. What has been reported, in the Chinese media, is that she died in a road accident sometime in 2000, shortly after she was divorced from her husband. And that at least one vehicle with a military license plate may have been involved in the crash.

Fourteen years later, investigators are looking into her death. Their sudden interest has nothing to do with Wang herself. It has to do with the identity of her ex-husband — once one of China's most powerful men and now the prime target in President Xi Jinping's anti-corruption campaign.

Investigators are probing the death of the first wife of Zhou Yongkang, China's retired security czar, a source with direct knowledge of the investigation said. They are looking for evidence of foul play by Zhou in the crash, the source said.