A former teacher of Mohammed Emwazi who became ‘Jihadi John’ has told Sky News he was involved in bullying allegations when he was a student.

But she said there were no signs at school he would become the Islamic State militant who is believed to have murdered at least five Western hostages.

However, the former teacher, who does not want to be named, said Emwazi had some “issues” at school.

She said: “There were examples or instances of arguments with other boys and students that did lead to allegations of bullying.

“But they were dealt with through normal school procedures and nothing stood out that was particularly concerning.”

She said there were no concerns about the radicalisation of pupils while she was working at the school and teachers “worked hard on promoting citizenship and family values”.

And she did not sense that there was extremism in the community at large because the school would have picked up on it, addressed it and “would not brush it under the carpet”.

The woman said Emwazi was “quite successful academically”, went on to do A-Levels at the school, had a small group of friends, and enjoyed and was passionate about football.

She added: “There was nothing that made me think he was unhappy or depressed. I think he enjoyed a laugh and a joke with his friends.

“There was no indication he was any different to any other young man growing up.”

Emwazi appeared in videos released by IS which showed the killings of Westerners, including of Britons Alan Henning and David Haines.

When she learned that Emwazi was the masked man in the videos, she said she was “extremely shocked and disturbed by it”.

She said: “It’s incomprehensible to me that a young person who appeared to have such a positive route into adult life could become the monster that he appears to have become today.”

“I keep asking myself over and over again why, how did this happen? What could possibly have changed in his life to take him down this path? I’m not sure we will ever know the answer.”

Meanwhile, a former boss of Emwazi has said he was “the best employee we ever had”.

He was “very good with people” and was “calm and decent”, according to the head of an IT firm in Kuwait, which hired the then 21-year-old as a salesman.

He also expressed shock the person he had known was behind the reign of terror in the IS videos.