The Idaho Medical Association says the U.S. Department of Justice is investigating whether some doctors in the state violated federal antitrust laws with how much they charged and by refusing to treat some patients.

The association revealed the investigation to its 2,400 members earlier this month in a memo obtained by the Idaho Statesman.

The association says it has been ordered to turn over records dating to January 2005, and that federal authorities are also investigating the Idaho Industrial Commission. The commission pays doctors to treat patients through its worker’s compensation program.

The association also says the government has demanded records from the Idaho Orthopaedic Society. (AP)