Timeline: Life and career of Ling Jihua, the disgraced top aide of former Chinese leader Hu Jintao
Ling Jihua, the one-time top aide to former president Hu Jintao, is being investigated by the Communist Party's anti-graft watchdog, it said on Monday.
Ling, 58, was under investigation for "suspected serious disciplinary violations", a term that usually refers to corruption, a statement read.
The announcement comes two years after Ling's political career was dealt a major blow with the controversy surrounding the death of his son Ling Gu in a Ferrari crash in March 2012.
It marks the fall from grace of a man poised to join to highest levels of power in China prior to the fatal accident.
Members of his well-connected family have also been probed in his home province Shanxi over allegations of graft.