ALBERT LEA (AP) - A doctor's complaints may bring new life to concerns about antitrust violations at the Mayo Clinic in southern Minnesota.

Dr. Matthew Kumar chairs the Department of Anesthesiology at Mayo Clinic Health System in Albert Lea and Austin. Kumar recently told attorney David Walker that he has filed four antitrust complaints against his employer since 2015.

Walker has forwarded Kumar's complaints to state Attorney General Lori Swanson and Democratic U.S. Rep. Tim Walz of Minnesota. Walker previously has requested officials look into antitrust concerns relating to Mayo Clinic's plans to move some services from its Albert Lea facility to its Austin location.

One complaint says Mayo Clinic is a health care monopoly that's eliminated competition in more than 70 communities in the Midwest.