BEIJING, Jan. 8 (Xinhua) -- China's National Audit Office (CNAO) discovered 7.1 billion yuan (816 million U.S. dollars) in illegally used social security funds in 2006, said Auditor-GeneralLi Jinhua on Monday.

The 7.1 billion yuan in social security funds were either illegally borrowed, used or deposited. The amount includes 2.3 billion yuan that was misused before 1999.

The CNAO audited the pension fund for enterprise employees, the medical insurance fund for urban employees and the unemployment insurance fund in 29 regions and five selected cities, said Li at the annual conference of national auditing authorities.

Li said the auditors audited seven special funds in 2006, covering a total of more than 1 trillion yuan (128.2 billion U.S. dollars).

The seven funds are the fund for transfer payments to local governments, the social security fund, the public housing fund, the natural forest conservation fund, the fund for resettlement and control of geological disasters at the Three Gorges areas and the fund for the control of sand storms in the Beijing-Tianjin region.

Li said that the management and use of the funds was generally good despite the problems discovered.

The audit of the Three Gorges resettlement fund discovered 200 million yuan were illegally claimed or used and five cases of misappropriation have been handed over to judicial institutions.

Li said this year the CNAO will strengthen auditing and supervision of the public service sectors as well as special funds covering agriculture, education, medical, social security and environmental protection.