A Missouri man who resigned from his job as an elementary school principal this month was arrested Wednesday on charges alleging that he had been dealing heroin.

Joshua Foust, 33, is charged with possession of a controlled substance with the intent to deliver. He is jailed on $100,000 bond and will be arraigned Friday.

Patti Talbert, the director of the Northeast Missouri Drug Task Force, said there is no evidence that Foust dealt drugs to students or staff while he was principal of A.D. Stowell Elementary School in Hannibal, where he grew up, or that he did so on school grounds.

Officers arrested Foust just after midnight after he arrived back in Hannibal, a city about 100 miles northwest of St. Louis. He had been in Texas, apparently for something related to his new job, and had informed the authorities that he would be returning and was being cooperative, Talbert said.

"It's very sad," Talbert said.

Foust's 31-year-old brother, Samuel Foust, and a third man, 32-year-old Ryan Thompson, were also arrested on drug charges as part of the same investigation. All three men remain jailed and online court records didn't list an attorney for any of them.

Joshua Foust resigned as principal on Feb. 2, saying he was taking another job. It wasn't clear if he knew at the time that he was under investigation.

Talbert said a tip sparked the investigation that led to a search of Samuel Foust's home last week. Officers found heroin and methamphetamine there and found heroin and methadone in the home of Joshua Foust, his wife and their young son, she said.

Talbert said the total amount of heroin seized could have produced around 800 capsules with a street value of between $8,000 and $12,000.

Foust grew up in Hannibal, a city of 18,000 residents best known as the boyhood home of Mark Twain, and graduated from Hannibal High School in 2000. He returned in 2011 to take the principal job, which paid about $65,000 annually. His wife, who is a teacher, is not under investigation, Talbert said.