The BBC confronted a Finnish neo-Nazi who shared arson instructions online with British rioters last summer.
This 20-year-old was the administrator of the group Southport, wake up in the messaging application Telegram, where he was known as "Mr. AG".
He published an arson manual, which was pinned to the top of group members' correspondence.
In late July and early August, this group was instrumental in helping to organize and challenge protests that turned into violence in England and Northern Ireland.
- How crime led to riots: What's happening in Great Britain
- Far-right group uses sports to 'create paramilitary'
- A neo-Nazi who converted and became a fighter against extremism
We found Mr. AG, whose real name is Charles Emanuel Miko Rasanen, in an apartment on the outskirts of the Finnish capital, Helsinki.
From there, more than 1.600 kilometers from Southampton, this neo-Nazi took on a prominent online role during the unrest in Britain.
On the twenty-ninth of July, just a few hours later the murders of three girls at a dance class in Southampton, a group was founded Southport, wake up.
Within days, it grew to more than 14.000 members.
Rasanen - or Mr. AG, as he was known online - helped run the company in this group.
The group organized the first protests in the UK, on St Luke's Road in Southampton, the day after the murders.
That protest later turned into a riot.
Before Telegram shut down this group, a number of other protest locations were advertised, as well as a list of a dozen refugee centers suggested as potential targets.
Along with that list, Mr. The AG posted a handbook on arson, writing: "Something you might find amusing to read."
This manual is believed to have been written by a Russian fascist group declared terrorists in their country.
It details how to evade the police and encourages attacks on Muslims and Jews.
Under the post, other members wrote aggressive and offensive comments, including: "I'm ready for these migrants," while another describes the "infiltrators" as "a bunch of idiots who underestimate white people."
Mr. AG pinned the post to the top of the group, meaning it was in front of all 14.000 members as soon as they logged in.
At that time, several riots broke out across Great Britain.
The BBC traveled to Finland to confront Rasanen - having previously emailed him.
He refused to answer our questions, but he did not deny that he sent those posts or that he was an administrator in the group Southport, wake up.
Before we parted, he accused the BBC of harassment and called the police.
On his Telegram accounts, Rasenen expresses admiration for Hitler and promotes the neo-Nazi group Nordic Resistance Movement, which is banned as a terrorist organization in the US.
He also posts voicemails - in one he describes himself as a "National Socialist" while in another he calls for the genocide of the Jewish people.
Veli-Peka Hamalainen, an investigative journalist at Jle, Finland's national broadcaster, says Rasenen has been active online for "many years".
Hamalainen's team also spoke to him about his role in the British riots.
He believes that Rasanen's participation in the group Southport, wake up turned him from a lone extremist into someone with an audience of thousands.
"This is an example of how lone Internet warriors behind a keyboard can become dangerous," says Hamalainen.
He says he has seen Finnish police files, which state that Rasanen was investigated when he was a teenager for making illegal threats, but that he was never charged with a crime.
The BBC also learned of Rasanen's previous online links with the UK-based far-right nationalist group Patriotic Alternative (PA).
He was an active member of the gaming group's private chat, and his posts were shared by key figures in the PA, according to the British anti-fascist research group Red Flash.
These include the regional Yorkshire organizer of the group Sam Melija, who ended up in prison earlier this year for spreading racial hatred.
At the time of the British riots, a post by Mr. AG's statement read: "When will the same violence reach Northern Europe?".
The spokesperson of the Red Flash, who first revealed the true identity of Mr. AG and his connection with Sauport, wake up, says that Rasenen must answer for what he did.
"What we have here is a case of a young man sitting at a keyboard in another country instigating racist violence in Britain," he says.
"It exposes the transnational nature of the far right in the world today."
The BBC contacted the Patriotic Alternative and, although this group refused to answer our specific questions, it did say that what Mr. AG posted on PA's public channel was "okay" and that PA did not participate in what Mr. AG posted in other Telegram groups.
Speaking to the BBC, the government's independent assessor of terrorism legislation, Jonathan Hall CC, said: "If Rasanen was physically present in the UK he would be arrested and prosecuted under the Terrorism Act 2006."
Hall estimates that at least half of prosecutions related to terrorist propaganda last year involved the Telegram app.
Finland does not have an extradition agreement with Great Britain, since the latter signed an exemption from the pan-EU agreement in 2021 after Brexit.
The British government declined to comment on whether an extradition request had been made or whether anything else had been done in connection with the case.
The BBC is not aware of any arrest warrants being issued.
Finland's National Police Board says it is "aware of the case" but cannot comment further.
A Telegram spokesman told the BBC that its moderators shut down British channels that called for violence as soon as they were discovered in August, including Southport, wake up.
"Of course, we are ready to cooperate with both the British and Finnish governments on this issue through the appropriate channels," Telegram said.
A British government spokesman says it is working rapidly to implement the Online Safety Act, which requires social networks to remove illegal content and prevent the spread of misinformation.
"We will not allow the Internet to serve as a haven for those who wish to bring discord into our communities," the spokesman said.
Additional reporting: Rebecca Vern, Erika Benke, Philip Edwards and Shayan Sardarizadeh
BBC is in Serbian from now on and on YouTube, follow us HERE.
Follow us on Facebook, Twitter, Instagram, YouTube i Viber. If you have a topic proposal for us, contact us at bbcnasrpskom@bbc.co.uk
Bonus video:
