LONDON: The man who became the Islamic State militant known as “Jihadi John” was a relatively hardworking student who showed no signs of being radicalized, his former school principal said Monday.

Jo Shuter, former head teacher at Quintin Kynaston Academy in London, told the BBC that Mohammed Emwazi was a “hardworking and aspirational young man” when she knew him as a teenager.

“He was quiet, he was reasonably hardworking,” Shuter said. Emwazi had “adolescent issues” and was bullied at school, she added, but he eventually settled down and did well enough academically to be admitted to the university that was his first choice.

“I can’t stress enough, he wasn’t a huge concern to us,” she said.

Emwazi was revealed last week to be the masked Islamic State militant known as “Jihadi John” who appears in several online beheading videos brandishing a large knife.

Authorities are working to understand how he became radicalized.

Shuter said neither Emwazi nor other students showed signs of embracing radical causes while at school.

Two members of Kuwait’s so-called “stateless” community say “Jihadi John” was born to an undocumented family in an impoverished corner of Kuwait.

They told The Associated Press on Monday that family members of Emwazi in the Gulf nation have been instructed by authorities not to speak to the media.

A family acquaintance described him as a polite young man, almost timid in nature. He agreed to be identified only by his first name of Tareq, fearing government retribution.

He and activist for stateless rights Abdul Hakeem Al-Fadhli said the family lived in the run-down Taima area of Jahra, a city on the outskirts of Kuwait City.