COLUMBIA - Seven golf courses and three other pieces of property are being audited by the S.C. Department of Revenue to see whether their owners abused a federal law intended to open land for public use or to save pristine environments.

All the golf courses are private and the five largest are in exclusive gated communities, said Burnie Maybank, S.C. Department of Revenue director.

Combined, the owners of the 10 properties could be claiming millions of dollars in federal charitable tax deductions, Maybank said. The landowners are receiving millions of dollars in state tax deductions as well.

Eventually, the audit could result in the property owners paying back taxes for every year they benefited from the deductions, Maybank said. The Revenue Department also could seek negligence penalties or open civil fraud cases.

"I can tell you there are cases where we will seek charitable fraud," Maybank said.

Maybank testified about the abuse of conservation easements June 8 before the U.S. Senate Finance Committee. In his statement, he addressed abuse by golf courses and real estate developers.

"I seriously question whether the U.S. Treasury should subsidize any golf course development, public or private," Maybank said. "In particular, I do not believe the U.S. Congress ever intended to give huge charitable deductions for the preservation of a golf course in an exclusive gated community."

In a conservation easement, the landowner agrees with a nonprofit group to restrict development of the property.

In exchange, the owner receives a tax break while keeping and using the land. The nonprofit is responsible for making sure easement terms are followed.

The land is supposed to meet certain needs, such as public recreation or preservation of a unique habitat, such as Lowcountry wetland where ospreys, woodpeckers, alligators and other wildlife live.

There are instances where golf courses could qualify, but Maybank does not think the links in gated communities fit the bill.

Developers are watching the federal government to see if changes are made.

Earl McLeod, executive director of the Homebuilders Association of Greater Columbia, said the easements have been good for developers who use them to keep open space in communities.

"It's a viable tool for developers, and it's good for the community," he said.

Maybank's department began its investigation after the Washington Post published articles about abuses around the country. At the same time, the Internal Revenue Service is cracking down on the abuse, and Congress is considering legislation to curb the practice.

The state Revenue Department first examined 110 easements worth more than $1 million each. The easements were granted between 2001 and 2003, Maybank said. The department is in the early stages of looking at another 50 easements, he said.

So far, the 160 easements under examination give landowners the potential to collect more than $300 million in federal charitable tax deductions, Maybank said.

In his report to Congress, Maybank said the instances of abuse were few but result in millions of dollars in lost tax revenue when they occur. Hence, an audit of the 10 properties.

Maybank could not release the names of the golf courses or other landowners because of privacy laws. He did say in testimony that the majority of golf course and developer easements seemed to involve the same land trust and some of the same appraisers and consultants.