China has opened an investigation into the head of its top insurance regulatory body, the anti-corruption watchdog said yesterday in an announcement that could signal problems for some of the country's most powerful companies.

Xiang Junbo is being probed for "suspected serious violation of the Party's code of conduct," the Central Commission for Discipline Inspection said in a brief statement on its website. The phrase is often a euphemism for corruption.Xiang took the top spot at the China Insurance Regulatory Commission in 2011 after heading the Agricultural Bank of China, one of the biggest state banks.

Various Chinese regulatory agencies have trained their sights on the insurance industry, complaining about companies' use of their financial holdings to fund risky acquisitions in real estate and unlisted equities.

In February Beijing announced investigations into several major insurance companies, including Evergrande Life and Foresea Life, for alleged market manipulation.