The ruling Communist Party's Central Commission for Discipline Inspection (CCDI) published a one-line statement on its website on Saturday, providing no other details about Cai's suspected wrongdoing.

Cai, a 30-year oil industry veteran, was named to lead Sinochem in 2014, after a long career at China Petroleum and Chemical Corp (Sinopec) where he was previously a Communist Party committee member, senior vice president, and Sinopec Corp's general consul.

In October, Cai also was named chairman and non-exeuctive director of Hong Kong-listed China Jinmao Holdings Group Limited <00817.HK>, a Sinochem Group real estate subsidiary.

Sinochem Group, formerly China's monopoly oil trader until 1993, has diversified businesses in oil refining, chemicals trading, oil and gas explorations and real estate development.

Cai is the latest state-owned enteprise executive to be caught in ruling the Communist Party's investigations into corruption. In December, CCDI said it was investigating the chairman of state-run China Telecom Corp Ltd was under investigation for alleged disciplinary violations. He later resigned.

(Reporting by Matthew Miller; Editing by Andrew Heavens)