Updated

Investigators combing the country for a 50-year-old teacher who is believed to have run off with his 15-year-old former student say the pair had a “romantic interest in each other.”

Tad Cummins and Elizabeth Thomas -- who were once allegedly caught kissing in a classroom -- haven’t been seen since March 13. But as officials continue their hunt for the pair, new evidence is emerging to show a “romantic” relationship developed between them prior to the disappearance.

Cummins and Thomas wrote emails to each other and saved them as drafts in a folder of Cummins’ school email account, Maury County District Attorney Brent Cooper told WAAY on Friday.

“They would write the message and let it save as a draft,” Cooper said. “The other person would log in, read the message and then delete it and then write another message that was saved as a draft.”

He added: “If you read them you would immediately recognize you are reading messages between two people who have a romantic interest in each other.”

A string of romantic posts appeared on what was believed to be their Instagram accounts as well. One post from the teen's page read "Every Beauty needs her Beast to protect her from everything but him," credited to poet N.R. Hart.

One of the email drafts shared with WAAY begins with Cummins telling Thomas that he “saw you standing next to you [sic] backpack this morning.”

“And [Cummins] makes a reference to a body part of hers and how nice that looked,” Maury County Sheriff’s Department spokesperson Marcus Alright said.

On Tuesday, the Tennessee Bureau of Investigation tweeted a photo from January showing Cummins and Thomas gazing at each other “days before his alleged inappropriate contact with her.”