Former National Action member Benjamin Hannam became the first ever British police officer to be convicted of a terror offence on 1 April.
The 22-year-old applied to join the Metropolitan Police in July 2017 and started as a trainee on 26 March 2018.
He passed vetting checks, completed training and was a probationary constable in an emergency response team by the time of his arrest on 5 March 2020.
Hannam was only exposed as a former member of National Action because anti-fascists leaked data from the fascist Iron March forum.
The Metropolitan Police said a disciplinary hearing held on Wednesday found that his actions amounted to gross misconduct.
The force said Hannam resigned following his trial but was formally dismissed without notice.
A spokesperson for the Metropolitan Police said the process took three weeks and “could not have happened faster” because of regulations that meant it could not be started until Hannam was convicted.
He then had to be served documents and given a minimum time to respond before the hearing.
Assistant Commissioner Helen Ball said he had “harmed public confidence” in policing and the reputation of the Metropolitan Police.
“PC Hannam has knowingly and intentionally remained a member of a proscribed organisation, made false statements, retained possession of terrorism-related documents and a prohibited image of a child,” she added.
“He had at every stage the option not to embark on this course of conduct and to move away from it and did not do so.
“In addition, PC Hannam has been convicted of six separate criminal offences. It is entirely unacceptable for police officers who are responsible for enforcing the law to break the law themselves.”
His trial heard that he became involved with National Action in 2016 and continued activities with a successor group after it was banned in December that year.
Prosecutor Dan Pawson-Pounds told the court Hannam demonstrated an “adherence to fascist ideology and a potentially veiled but nonetheless evident neo-Nazi mindset” in the period covered by the charges.
“He had been a member, and active recruiter before proscription, and continued to be so afterwards, whilst taking precautions to move and conceal incriminating evidence,” he added.
He was convicted of membership of a terrorist organisation and also admitted possessing a prohibited image of a child.
The constable, from Edmonton in London, was also convicted of two counts of possessing information useful to a terrorist – the 2011 Norway attacker Anders Behring Breivik’s manifesto and a “knife combat” document.
Hannam was found guilty of two counts of fraud for lying on police application and vetting forms.
They asked recruits if they are, or have ever been, members of the British National Party (BNP) or a similar organisation “whose aims, objectives or pronouncements may contradict the duty to promote race equality”.
Hannam denied being a member of National Action at any point during his trial, and said that even if he had been he was right to answer “no” on the forms because it was not similar to the BNP.
Scotland Yard said that if he had ticked yes, he would have been barred from joining the force.
Hannam was involved with National Action from March 2016 and it was banned as a terrorist organisation by the government in December that year.
He then took part in activities by its successor group NS131, which was an alias used to evade the prohibition until it was also banned.
His trial heard he travelled to National Action meetings with senior members, including the group’s co-founder, attending its 2016 conference, boxing camps and graffiti events.
Hannam appeared in a promotional video for NS131 and in a photograph alongside other members, in front of a National Action flag.
Investigators believe Hannam had ceased active involvement with the group by October 2017 – almost three months after he applied to become a police officer.
Scotland Yard said “all known involvement” was over by the time he started training in March 2018.
Officials said Hannam’s fellow officers did not raise concerns about his ideology or behaviour over his two years of service, and were “shocked” by the investigation.
In a witness statement, one of Hannam’s superiors said he had not drawn attention “for anything other than being immature and a slow learner”.
Another superior described the defendant as “quiet” and socially awkward, saying he “was considered quite an immature individual by his peers”.
The Metropolitan Police said “thorough checks” were carried out on the cases and incidents Hannam had dealt with, as well as his use of the Police National Computer database, and that nothing of concern was found.