The chairman of China Investment Securities, a brokerage owned by China's sovereign wealth fund China Investment Corporation, has been removed from his post following a corruption investigation, the communist party's graft watchdog said.

Long Zenglai is the first senior executive at a securities firm to be caught up in China's wide-ranging anti-corruption campaign.

Long is alleged to have spent thousands of yuan on organising banquets at luxury restaurants since 2013. He also used public funds to pay for rounds of golf and spent company money to finance the publication of his poetry, said the Central Commission for Discipline Inspection on its website.

Chinese President Xi Jinping has vowed to go after powerful "tigers" as well as lowly "flies" in his struggle against corruption, warning that the problem is so bad it could affect the party's grip on power.

The campaign has targeted both politicians and business leaders, with financial sector executives among the more recent targets.

In a separate announcement, the graft watchdog said an inspection at China National Nuclear Corporation had found repeated violations of financial discipline including misuse of funds for tourism and illegal allocation of benefits.

It also found evidence of major decisions taken without adequate research, investment projects that had led to business risks, a lack of sufficient management of materials procurement and some projects operating illegally.

CNNC, one of China's two state nuclear reactor builders, recently listed its subsidiary China National Nuclear Power Co Ltd (CNNPC) on the Shanghai stock exchange in the country's largest initial public offering (IPO) since 2011.