GOP frontrunner Donald Trump says he’s considering filing a formal complaint against Sen. Ted Cruz (R-TX) for alleged “voter fraud.”

“I probably will,” Trump said when asked about taking the issue to court during an interview on Boston Herald Radio.

Trump was referencing Cruz’s campaign sending out notifications that Dr. Ben Carson was withdrawing from the race during the Iowa caucus, suggesting voters select another candidate, based off of a false report by CNN.

Cruz has since apologized and Carson has accepted.

Trump stated that Cruz’s action was “one of the most disgusting things I’ve ever seen.”

“What he did is unthinkable,” Trump added. “He said the man has left the race and he said it during the caucus. And then when clarification was put out by Ben Carson saying it’s untrue, they got a statement and they didn’t put it out.”

“They apologized after the caucus was over. How does that help?” Trump questioned.

“It’s total voter fraud when you think of it, and he picked up a lot of those votes, and that’s why the polls were so wrong, because of that,” he challenged.

Trump also referenced controversial campaign mailers Cruz sent out in Iowa during the interview.