ROCHESTER  (AP) -— Mayo Clinic is accused of filing false claims for federal reimbursement.

A civil complaint filed Monday accuses the Minnesota nonprofit of improperly billing for surgical pathology services that were never rendered. The federal complaint intervenes in an existing lawsuit against Mayo and related entities.

The dispute revolves around the preparation and examination of human tissue slides. Mayo spokesman Bryan Anderson says Mayo discovered a billing error in 2007, corrected it and voluntarily refunded nearly $243,000 to the government. Anderson says Mayo has fully complied with the law.

Assistant U.S. Attorney Chad Blumenfield says the government doesn't think that amount is enough, but he said it's hard to know how much it should be. Blumenfield says the government believes the improper billing went on for many years before 2007.

(Copyright 2010 The Associated Press.  All Rights reserved.)

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