HELENA, Mont. -

The Montana Democratic Party has filed a complaint with the Federal Election Commission seeking an investigation into connections between U.S. House candidate Ryan Zinke and the super PAC he founded.
    
The complaint filed Monday says the Special Operations for America political-action committee is coordinating with the Zinke campaign committee. It says the two groups used the same research consultant.
    
Super PACS are allowed to spend money to support or oppose candidates, but they're not allowed to coordinate with them.
    
Zinke and his campaign did not immediately return a call Monday.  Zinke said previously he resigned from SOFA weeks before announcing his campaign to make sure everything was "squeaky clean."
    
Two Washington, D.C.-based advocacy groups have filed a similar FEC complaint.
    
Zinke faces Democrat John Lewis in November's U.S. House election.