A group of high school students in Pekin, Ill., were suspended last week after school officials suspected the mints they were eating were actually illegal drugs.

Jason McMichael, the father of one of the students, told the Journal Star that his 17-year-old son Eric was suspended for two days from Pekin Community High School and not allowed to attend the school's homecoming festivities after staffers found four students eating energy mint tablets that are marketed like caffeine energy drinks.

McMichael said he received a phone call from the dean's office informing him of his son's suspension and that the teen was being monitored by the school nurse for an elevated heart rate—though McMichael doesn't believe it was due to the energy mints.

"He's never been in trouble," McMichael said. "He was probably just nervous."

Eric McMichael said he and three others were eating Revive tablets—touted as "nature's energy mints"—in the school cafeteria when they were disciplined.

"People bring energy drinks to school every day," the teen told Central Illinois' WMBD-TV. "I see this every day and we get in trouble for energy mints?"

According to EnergyFiend.com, each mint contains 101 milligrams of caffeine along with guarana, green tea, ginseng, acai, mangosteen and goji. The Revive brand is endorsed by several MMA fighters and fitness pageant contestants.

McMichael's father said school officials later admitted they did not know if the chewable, unmarked mints were, in fact, illegal drugs but upheld the suspensions anyway, saying the teens displayed "gross misconduct for taking an unknown product."

"Now they know nothing illegal happened," McMichael said on Friday, "but they're still pursuing the suspension."

Superintendent Paula Davis told the paper that while she was not able to discuss the incident, school officials would have been within their rights to discipline the students if they were seen "ingesting things that look like unmarked pills."