The first British police officer to be convicted of belonging to a neo-Nazi terrorist group is facing jail when he is sentenced on Friday.

Ben Hannam, 22, was found guilty of membership of banned right-wing extremist group National Action (NA) following a trial at the Old Bailey.

He was also convicted of lying on his application and vetting forms to join the Metropolitan Police and having two terror documents detailing knife combat and making explosive devices.

Hannam, who had been suspended from the force, has since been sacked for gross misconduct.

The disgraced ex-officer, who is on bail, will return to court on Friday to be sentenced by Judge Anthony Leonard QC.

Hannam had been working as a probationary officer for the Metropolitan Police for nearly two years before he was found on a leaked database of users of extreme right-wing forum Iron March.

As early as May 2014, he had expressed intolerant views, writing: “I’m not racist, I just don’t like people who’s (sic) skin is darker than mine!”

His former history teacher said Hannam made “inappropriate” and “offensive” anti-immigration comments during a school Brexit debate.

In March 2016, he had signed up to Iron March when he joined the London branch of neo-Nazi group NA.

Hannam, who has autism, told jurors he was “desperate to impress” an older NA organiser who gave him free stickers and badges.

Hannam went on to try to recruit a new member via Iron March, jurors were told.

He told him that most NA members agreed the “Hitler was right” slogan was “a bit too edgy” but added: “Then again, it is pretty funny and we all know our stance on the big man.”

At the NA national conference in Liverpool in April 2016, Hannam posed in an official photograph on Crosby Beach.

On December 16 2016, NA was proscribed after it glorified the murder of Labour MP Jo Cox.

However, Hannam continued to meet high-profile figures in the neo-Nazi group.

Between January and July 2017, he saw them in pubs, at an outdoor boxing event, and when he spray=painted an NA symbol in a storm drain.

On July 19, days after the graffiti trip, which was filmed for a promotional video, Hannam applied to join Scotland Yard.

He fraudulently denied he had ever been a member of the British National Party “or similar organisation”.

When officers searched his bedroom last year, they found Nazi-style posters, notes detailing his membership of NA, as well as NA badges and business cards.

He had stored on a USB stick two documents said to be useful to a terrorist.

Mass murderer Anders Breivik’s manifesto contained guidance on making radiological, chemical and biological weapons, and improvised explosive devices, while the second document detailed how to carry out a fatal knife attack.

But Hannam denied he had ever been a member of NA before or after it was banned.

He told jurors he had been attracted to fascism at the age of 16 because of its bold artwork, and contacted NA after seeing propaganda online.

“I was under the impression this was some kind of youth network,” he said.

“I have never been stickering with NA, nor have I done banner drops. I stuck to social activities.

“Most of the time was going to the pub and going for walks. Other times camping or going boxing.”

Following his conviction, it emerged that Hannam’s legal team had asked the judge for an indication of the likely sentence if he pleaded guilty before trial.

Judge Leonard declined but said Hannam, of Edmonton, north London, would face jail, even if he admitted the charges.

The media had been banned from reporting Hannam’s subsequent trial as he had been facing separate unrelated allegations.

However, on the day the jury retired to consider verdicts, he pleaded guilty to possessing an indecent image of a child, meaning reporting restrictions could be lifted.

Scotland Yard has said that checks on Hannam’s work revealed no complaints from colleagues or members of the public.

Commenting on his dismissal, Assistant Commissioner Helen Ball said: “In behaving as he did, he has without question harmed public confidence in, and the reputation of the MPS, by belonging to an organisation that espouses the views of National Action, which are so wholly an antithesis of the Met’s values and the traditions of British policing.”