The Minnesota Republican Party is asking the state attorney general to investigate claims that a GOP challenger to the party’s endorsed candidate violated state law by “robocalling” voters before the primary for a western Minnesota congressional district.

In a letter sent Thursday to state Attorney General Keith Ellison, Minnesota GOP Executive Director Becky Alery alleges that “numerous Republican voters were contacted by the Noel Collis for Congress Committee via message by an automatic dialing-announcing device.” The letter claims the calls lacked a live operator and that the targeted voters did not opt in to receive prerecorded messages, running afoul of state laws on automated calls.

The Collis campaign disputed the allegation, saying it is “utilizing a state of the art ‘server-to-server’ communications system” that adheres to state law.

Collis, a physician from Albany, is one of five Republicans competing in Tuesday’s primary for the Seventh Congressional District. The winner will take on longtime U.S. Rep. Collin Peterson, a Democrat representing a district that President Donald Trump won by a wide margin in 2016.

Michelle Fischbach, a former state senator and lieutenant governor, won the Republican Party endorsement after a bitter and lengthy convention fight in June. But a number of candidates, including Collis and Dave Hughes, an Air Force veteran who won the nomination in 2016 and 2018, opted to remain in the race through the primary.