The last five words were underlined, for emphasis.

Now, a number of parents are claiming that the teacher put their children’s assignments up for sale online, without their knowledge — emblazoned on almost 3,000 items, including mugs, ornaments, cushions and shower curtains, at prices up to $120.

A legal letter sent to the school board and teacher on Tuesday alleges that the teacher, named as Mario Perron, listed the artworks “without the consent of their creators, in bad faith, and in violation of all laws related to the intellectual property of an artist.”

Joel DeBellefeuille initiated the legal action after his 13-year-old son Jax came home from school one day last week and told him that the students had come across their works for sale while searching the internet to learn more about their teacher’s art.

“This guy basically had his own little, you know, sweatshop of children,” DeBellefeuille said. “It’s insane. I’m still in disbelief.”

Perron did not immediately respond to an emailed request for comment. The school board confirmed Tuesday that it had received the legal notice and had forwarded it to its insurers.

“The Lester B Pearson school board is aware of the situation and is taking these allegations very seriously. An investigation is underway so the school board cannot comment on this matter any further at this point,” Darren Becker, the school board’s communications director, said in an email.

The legal notice, which seeks 350,000 Canadian dollars (almost $260,000) for breaching the country’s copyright act, as well as for moral and punitive damages, alleges that the artworks used by Perron “for commercial purposes bear the name of the student as the author, easily allowing for identification.”

It also alleges that “the portraits represent the students, causing them significant moral harm and could be used, in the future, to hurt or bully them psychologically,” and calls for Perron to be suspended from teaching the students and for the artworks to be removed from all platforms.

The “Creepy Portrait” works were named after the students who drew them and were all signed “Mario MJ Perron,” according to screenshots from one art website viewed by The Washington Post. (The website’s purchasing function was disabled and the artist’s name anonymized to M.P. after DeBellefeuille first posted about the incident on social media, but the products remained online for days.)

DeBellefeuille’s son Jax was away sick on the day of the assignment. But a portrait of him still appeared on the website — a dark, bloodied face on a blue background that was drawn by his classmate.

Edith Liard, whose daughter Jasmine Fahoume also took Perron’s art class, said that when Jasmine came home last week and said her teacher was selling the students’ artwork, “I didn’t believe her at first, so I had to look for myself.”

Jasmine, 14, appeared twice — both as an artist and as a subject. For her own painting, she drew a ghoulish, almost translucent face. In a phone interview, she described her portrait, drawn by a friend, as “a very bad likeness of me” — a kind of creepy Peppa Pig, with oversize features, a curly tail and a knife.

“It is a scandal,” Fahoume said.