Mark Kelly's campaign vehemently denied uncorroborated claims that photos, recently published by a conservative news site, show the former NASA astronaut dressing up for Halloween as Nazi dictator Adolf Hitler.
In statements provided by the campaign, four of the Arizona Democratic Senate candidate's classmates at the Merchant Marine Academy said Kelly, who's trying to unseat GOP appointee Martha McSally in a race that could determine control of the Senate, was falsely accused by National File.
"I attended the Merchant Marine Academy with Mark. I attended this event. This is not Mark in any of these photos," said class of 1986 alum Jennifer Boykin.
"I attended this event as well and am in this photo," fellow classmate Ed McDonald added. "This is a group from 2nd Company. Mark was not in 2nd Company, and that is not him in these photos."
Kelly's roommate Mark Baden also denied the veracity of National File's assertions.
"I was the First Rotation Regimental Commander," he said. "These photos are absolutely not Mark Kelly and anyone saying that is lying."
Another classmate - a Republican from Washington state - Peter Lindsey told the Kelly campaign that he had received a message on LinkedIn in September from an individual who "said he was working on a research project" about Kelly's days at the Merchant Marine Academy.
The campaign later identified the person as a paid consultant for a super political action committee -- Senate Leadership Fund -- related to Senate Majority Leader Mitch McConnell, R-Ken. It is spending tens of millions to help defeat the former Navy combat pilot.
The Kelly campaign shared with Fox News screenshots Lindsey provided of the interaction, as well as filing records from the Federal Election Commission showing payments to the PAC worker.
"They shared these photos and asked if the person in the costume was Mark Kelly. I told them no, and want to say again, Mark is not in those photos," Lindsey said. "I have spoken to numerous classmates about this evening, and they concur that he is not in any of these pictures. The people spreading these lies should stop."
Paul Sturm, who was Mark Kelly's classmate for four years at the academy and lived in the same dorm, concurred. "I can unequivocally say that Mark is not in the yearbook photo of my costumed classmates," he said.
In its article, National File asserted the black and white image -- which depicts a man with a thin, dark mustache wearing what appears to be a swastika and aviator-style sunglasses -- was Kelly and posted other photos from a yearbook reportedly dating to the mid-1980s. The website did not quote anyone confirming the images were of Kelly.
On Saturday, the younger Trump urged that Kelly drop the "pretend moderate act."
The elder Trump is engaged in a fierce election battle against former Vice President Joe Biden and is urging supporters to preserve Republican Senate control as well as return the House to Republicans.
The National File reporter who published the photos stood by his story in a statement to The Arizona Republic.
"I am frankly shocked that Mark Kelly would dare to deny this and at the mainstream media's inability or unwillingness to do their job and report the truth about the candidates seeking high office in the United States," Patrick Howley said.
Howley tweeted about his reporting on Friday night, telling followers that the Kelly campaign was "bungling" their "response operation" and that The Republic "would not confirm they verified the classmates or just got their statements from Kelly campaign."
National File previously broke the news that North Carolina Democratic Senate candidate Cal Cunningham had a secret romantic texting relationship with a woman who is not his wife. Cunningham has acknowledged the affair.
But, according to the Kelly for Senate Campaign, Howley's report is nothing more than yet another attack by allies of his Republican opponent.
"These aren't pictures of Mark, and he never dressed up in such a costume. The story is false and should be retracted immediately, and those who have spread this misinformation online should delete it. Anyone using it to try to smear a combat veteran should be ashamed of themselves," Mark Kelly for Senate Campaign Manager Jen Cox said in a statement.
While polls continue to favor Kelly, McSally has been on the offensive over the past couple of weeks.
The McSally campaign declined to comment on the photos.