A young man identified in media reports as the militant known as “Jihadi John” was a Londoner in his mid-twenties who travelled to Syria to join Islamic State militants in 2012.

Media reports suggest that the masked militant seen in numerous Islamic State propaganda and beheading videos is Mohammed Emwazi, a 26-year-old who was born in Kuwait and raised in West London.

Asim Qureshi, research director at rights group CAGE, said Thursday that the group has had a case file on Emwazi for years because of his allegations of harassment by security agencies in the U.K.

After watching a video of Jihadi John, Qureshi said Thursday that although “there were some striking similarities,” because of the hood he wears “there was no way he could be 100 per cent certain” that the man is, in fact, Emwazi.

At a press conference in London Thursday afternoon, Qureshi described Emwazi as a kind and polite young man who brought CAGE staffers treats in thanks for helping him with his case.

“You might be surprised to know that the Mohammed I knew was extremely kind, extremely gentle, extremely soft-spoken,” Qureshi told reporters. “He was the most humble young person that I knew.”

Emwazi’s identity was revealed Thursday in reports published in the Washington Post and on the BBC’s website. A person described as a “close friend” of Emwazi’s identified him in an interview with the Post.

Jihadi John has appeared in several ISIS videos, but his identity has never been confirmed by law enforcement agencies. He always appears with his face fully covered except for his eyes.

Last year, another young man from London, Abdel-Majed Bary, was identified as one of the men law enforcement agencies were looking at as they sought to confirm Jihadi John’s identity.

In the months leading up to the beheading of journalist James Foley last August, Bary had posted several pictures of himself dressed in fatigues and carrying high-powered weapons. He posted a photograph to Instagram of himself holding up a severed head.

Authorities have been working to identify the militants seen on the video of Foley’s beheading, and those of Steven Sotloff, David Haines, Alan Henning, Peter Kassig and others.

'Life will be harder for you'

In response to Thursday’s media reports identifying Emwazi, CAGE posted a detailed account of his life and recent travels to its website.

Emwazi was born in Kuwait in 1988 and moved to the United Kingdom with his family at the age of six, the agency says. He was raised in West London and earned a university degree in 2009.

The Washington Post reported that his degree was in computer programming.

According to CAGE, Emwazi first approached them in 2009 after he said he was detained, interrogated and recruited by British intelligence agency Mi5. Emwazi said he was stopped upon arriving in Tanzania for a safari holiday with friends.

Emwazi said he was interrogated by an Mi5 official, accused of trying to travel to join terrorists in Somalia, and then asked directly to work for the agency.

When he refused, Emwazi said the agent told him that he would be followed and that “life will be harder for you.”

CAGE says Emwazi suffered “harassment and abuse” at the ends of U.K. intelligence until he tried to return to Kuwait “to start a new life.”

Emwazi had planned to travel to Kuwait in 2010. The agency says Emwazi told them that he never got on the flight, despite having a fiancée and a job waiting for him.

“But now I feel like a prisoner, only not in a cage, in London. A person imprisoned and controlled by security service men, stopping me from living my new life in my birthplace and my country, Kuwait,” Emwazi is quoted as saying.

Emwazi alleged that officials in the U.K. pressured Kuwaiti officials to deny him entry to the country.

An attempt to change his name in order to travel did not solve the problem.

The agency says Emwazi sought various legal channels to clear his name and earn safe passage to Kuwait to start his life anew. But by March 2011, he “was becoming increasingly desperate about his situation.”

He also sent emails to Qureshi expressing frustration with problems facing Muslims around the world, from Chechnya to Iraq.

After a last meeting with Qureshi in January 2012, Emwazi did not contact the agency again.

The media reports suggest he travelled to Syria that year to join Islamic State militants.

Qureshi noted that Emwazi was “willing to engage in the system” and pursue appropriate legal channels to clear his name.

But his fate was ultimately determined by a security system in the United Kingdom “that can act with impunity, can destroy the lives of young people without any recourse or a way to challenge them in any effective way.”

People will start feeling like outsiders if they are treated that way, Qureshi said, and will “look for belonging” elsewhere.

“He was such a beautiful young man. Really,” Qureshi said. “It’s hard to imagine the trajectory, but it’s not a trajectory that’s unfamiliar to us.”