The teen met the substitute teacher during her junior high school studies in Hässleholm, southern Sweden, and kept in contact afterwards, wrote the Norra Skåne newspaper.
When the teen moved on to high school, the pair began exchanging text messages with a sexual content, including pictures.
The man later admitted to hearing”alarm bells” at the time, but sent the pictures anyway.
Not long after, however, the student demanded that the teacher pay her 300 kronor ($80) to keep her from showing the SMS to the man’s wife.
One text read: “Either give me 2,000 or you face tonnes of questioning and a fine and a phone call to your wife – what’s your choice?” the paper reported.
He slipped the money into her locker, but the woman wasn’t finished.
Over time, she extorted a total of 3,300 kronor from the man, which was deposited into her bank account. The bank statements have now been used as evidence.
The teacher admitted that he was so shaken by the ordeal that he considered suicide.
The young woman has since confessed to the crime.