BEIJING, Dec. 16-- China's graft authorities Tuesday pledged to step up regular internal inspections on state-owned enterprises (SOEs).

Hao Mingjin, vice minister of supervision, told an online press conference, to expect more internal inspections at SOEs.

The press conference was streamed on the CPC Central Commission for Discipline Inspection's (CCDI) website.

Since 2013, the Communist Party of China's (CPC) central authorities have dispatched inspectors to ministries, provincial governments, SOEs and public institutions.

Six SOEs have so far undergone inspections and, in the latest round, another three -- China State Shipbuilding Corporation, China Unicom and Sinopec -- will come under scrutiny.

Serious corruption issues remain in SOEs, including abuse of power and bribery, Hao said.

Chief executives at state-owned enterprises have been identified as "high-risk" positions and, should it be proved they are embroiled in graft, it is highly likely their subordinates are also involved, creating a graft gang, he said.

Many corrupt executives have abused their power to facilitate private companies run by their relatives and some of their illegal decisions have led to serious state losses.

Corruption has become much more subtle, with those involved using "legal covers" to hide any untoward activity, he said.

Hao attributed corruption to the loose management and discipline of Party organs in the SOEs these senior executives, who are mostly Party members, work for.

"An SOE executive should not consider the company his or her own business nor regard himself or herself a private business person," he said.