Sen. Roger Wicker of Mississippi was photographed Thursday not wearing a mask on a commercial airplane flight, which violates the airline’s rules.

Matt Harringer, a fellow passenger aboard the flight took the photo of Wicker and posted it on social media.

“I’ve seen enough Republican senators test positive to tweet this photo,” Harringer wrote in a tweet. “@SenatorWicker – because you refused to wear a mask on our @Delta flight last night, please let your fellow passengers know your status once you’ve been tested.”

USA Today reported that Wicker’s communications director, Rick VanMeter, said the senator had merely lowered his mask to eat a snack and “forgot to put it back up.”

“When he was reminded by a flight attendant, he put the mask back up,” VanMeter told the newspaper.

Harringer, however, disputed that claim, saying that Wicker didn’t have a mask on before the flight took off.

I’ve seen enough Republican senators test positive to tweet this photo. @SenatorWicker — because you refused to wear a mask on our @Delta flight last night, please let your fellow passengers know your status once you’ve been tested. pic.twitter.com/j2TW6g1gwO

— Matt Harringer (@MattHarringer) October 3, 2020

VanMeter said Wicker hadn’t been to any events at the White House and had not been around any of the people near President Trump who had tested positive for the virus.

Delta Airlines told USA Today that it was investigating the matter.