SHANGHAI - A total of 151 provincial-level officials and ministers have been audited as of the end of 2010, the National Audit Office (NAO) said at a news conference on Friday.

Higher-ranking officials were added as subjects of audits after the nation expanded the scope of the audit program in October 2010 - previously, only county- and lower-level Party and government officials were audited.

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Under the expanded program, leaders of public institutions and State-owned enterprises are also to be audited.

The NAO did not disclose the its findings in the audits of the 151 officials on Friday, but it said the audits have "functioned positively in supervising Party officials, building a clean and honest Party and promoting rapid and beneficial social development".

The audits of high-ranking officials come amid China's increased anti-corruption efforts this year, which the central government sees as crucial for the nation's social stability.

On Feb 12, Liu Zhijun, former minister of railways, was dismissed on suspicion of committing a "severe violation of discipline".

The Zhengzhou Evening News has reported that 11 provincial-level officials and ministers were removed from their posts in 2010.

The NAO said that it has not yet perfected its procedures for high-level audits because there is no previous experience to draw from.

In a document posted on its website on Friday, it vowed to broaden the financial audits of major government and Party officials as well as leaders of State-owned enterprises over the next five years.

The NAO said in the document that it will further develop the audits to serve as society's "immune system", thus contributing to the central government's anti-corruption measures.

The NAO said it will continue to raise the standards of its audits and the efficiency of its staff.