An retired from state-owned JAC in 2021 after 46 years, having served as chairman for nine years.

The Central Commission for Discipline Inspection said on its website that An was suspected of "serious violations of discipline and law" but did give any details of the case.

JAC did not immediately respond to a request for comment on Tuesday.

JAC partners with both Volkswagen and Chinese electric car firm Nio.

In 2017, JAC set up a 50-50 joint venture with Volkswagen focused on electric vehicles and the German automaker secured a controlling stake in the venture three years later after Beijing relaxed foreign ownership rules.

JAC is Nio's manufacturing partner. In December,Nio said it would take over some plant assets from JAC.

Volkswagen and Nio did not immediately respond to requests for comment on the investigation into An.

(Reporting by Beijing and Shanghai newsrooms; Editing by Edwina Gibbs)