A father of two looks out of his bedroom window to the suburban street below. Things have changed since the time last year that he felt trapped there: the police car stationed outside has gone, and the panic alarm has been removed. Yet the CCTV outside his front door is still there to remind him.

“There was absolutely no way I could’ve gone out there,” the 55-year-old said. “I did try and there was people coming out wanting to fight us.”

It has been a year since the Muslim ex-youth worker became a target for the far right after protesting against a 1,000-strong march in the city. A picture of him at the counter-protest was posted to a far-right Facebook group, calling him a “paedo” and “rape enabler”. Other Facebook users quickly found his address, posting details of his home, his cars, and his business.

Then someone claimed the man had been previously charged with sexual assaults. It was a lie, but it quickly took hold. “This post got shared all over Sunderland within a morning,” he said. Facebook eventually removed the posts after being contacted by a local MP’s office, but by then the lie had grown. “I couldn’t go to work for a while,” he said. “People were walking round saying ‘He’s a paedo.’ It ruined my business. It had an absolutely massive effect.”

The man was a victim of what Sara Khan, who leads the government’s Commission for Countering Extremism, described in a report last week as a worrying trend of far-right groups swooping into towns and cities and distorting the truth to turn residents against minorities, particularly Muslims. Khan’s report highlighted Sunderland as a city where high-profile far-right activists like Tommy Robinson exploited community tensions and “stirred up” local people who would not normally support the far right.

The windswept north-east city, a former industrial powerhouse, is not a hotbed of rightwing politics. In 2003, Sunderland decisively rejected the British National Party when it became the first local authority where the rightwing party contested (and failed to win) every seat.

But over the course of two years, a perfect storm of events saw Sunderland became the focal point for the far right in Britain. The city saw 13 marches in 13 months and a toxic atmosphere fuelled by national street protest groups and a stream of misinformation on social media.

Tensions began in September 2016, when a woman alleged online that she had been gang-raped by a group of Middle Eastern men. Her allegations were investigated by the police but the Crown Prosecution Service (CPS) found insufficient evidence for any charges. The woman’s story was pounced upon by local far-right activists and later picked up by Robinson, the English Defence League founder, who described it as “the case we can start the fightback”.

Robinson’s employer, the rightwing Canadian broadcaster Rebel Media, funded a solicitor to challenge the CPS decision – unsuccessfully – and bought a huge billboard in the city centre to draw attention to the case.

A series of increasingly ugly protests began, fuelled by unfounded conspiracy theories of a cover-up. The police, CPS and local newspapers were restricted in what they could say about the case given the woman’s legal right to anonymity, which remains in place despite Rebel Media identifying her in videos that amassed up to 200,000 views.

“Rebel Media did a tremendous job of stoking up fear in this city,” said Graeme Miller, leader of Sunderland city council. “There were hundreds and hundreds of people on social media talking about the crimes – crimes plural – that had been committed by multiples. All of that was wrong.”

In May 2018, tensions erupted again when four rapes were reported in the city within days. One of the attacks resulted in the conviction of two men for raping a woman at their asylum seekers’ accommodation; the other allegations were never proven.

A group calling itself Justice for Women and Children was born, organising rallies that, according to councillors, whipped up anti-migrant sentiment. One of its marches attracted about 1,000 demonstrators, mostly activists with the Democratic Football Lads Alliance. The group launched a helpline for victims and has since been described by anti-racism campaigners as the first prominent far-right group led by women – a claim denied by its organisers.

As tensions rose, Sunderland MP Julie Elliott and the council asked the Home Office for a temporary pause in the number of asylum seekers being sent to the city, citing the “re-emergence of tensions”. With only 400 asylum seekers – equivalent to 0.1% of its population and a third of its allocation – political rivals accused them of giving succour to the far right but, away from the protests, there had been underlying concerns about the concentration of asylum seekers in a small area of Roker, near the city centre.

The words “rape street” were sprayed on one row of houses where asylum seekers had been placed by the contractor G4S. Elsewhere in the city “Muslims out!!!” was sprayed on a mosque and the council received a string of unfounded complaints against Muslim taxi drivers. “It was just the perfect storm of ‘here’s another English city where white girls cannot walk the streets’ – which was entirely wrong,” said Miller.

The council leader said the city had since “reset itself” but that it took months of work to “drain the poison from what was a very tense situation”. Khan’s report praised council leaders for holding regular public meetings to try to counter misinformation and for working with police to put boundaries on the protests. A prominent speaker at the first Sunderland marches, Billy Charlton, was jailed last month for fuelling what the judge described as the “toxic atmosphere” in the city.

Volunteers said the majority of the city’s asylum seekers and refugees hardly noticed the increase in tensions, though some were warned about their safety. “A lot of the people who attend the marches are not from this area anyway – they’re the parasites that are feeding on what’s going on at the time,” said David Robinson, 44, a chef who helps run a community integration project in Roker.

But for the ex-youth worker who was targeted, life has turned on its head. He had to close his business, change the number plates on his car and install CCTV outside his home. As a proud mackem and a Muslim, he fears the rightwing marches will return unless more of the city’s 96% white population stand up in opposition.

“The majority of people in Sunderland are not racist,” he said. “I’m worried about where Sunderland is heading [because] there’s too many people walking around with their heads down, not looking at what’s going on.”