A “fanatical” neo-Nazi couple who named their baby son after Hitler have been convicted of membership of a terrorist group.

Adam Thomas, 22, and Claudia Patatas, 38, were found guilty of being members of the extreme rightwing organisation National Action, which was banned in 2016.

A jury at Birmingham crown court was that told the couple, from Banbury, Oxfordshire, gave their child the middle name Adolf, which Thomas said was in “admiration” for Hitler.

Photographs recovered from their home showed Thomas, formerly an Amazon security guard, cradling his newborn son while wearing the hooded white robes of the Ku Klux Klan.

Thomas, formerly of Erdington in Birmingham, and Patatas, a photographer originally from Portugal, were found guilty after a seven-week trial.

A third defendant, Daniel Bogunovic, from Leicester, was also convicted of being a member of National Action. The warehouse worker was a leading figure in the organisation’s Midlands chapter.

Jurors were told Bogunovic already had a conviction from earlier this year for stirring up racial hatred after being part of a group that put up offensive stickers at Aston University in Birmingham.

Thomas, a twice-failed army applicant, was also convicted of having a terrorist manual, the Anarchist’s Cookbook, which contained instructions on making “viable” bombs.

The crown’s case was that after being banned by the government in December 2016, National Action simply “shed one skin for another” and “rebranded”.

Jurors heard evidence of social media chats involving Thomas, Patatas and Bogunovic discussing what prosecutors have alleged was the banned group’s continuing operations under a different name.

The jury also heard that Thomas and Patatas plastered National Action stickers in public locations after the ban, while Bogunovic was calling for a “leadership” meeting in a chat group for senior members in April 2017.

Thomas told the trial he had had a shaved head from the age of five and that his stepfather was in Skrewdriver, which he described as a “white power” band.

Asked by his barrister, Frida Hussain, whether he was a racist, Thomas replied: “Yes.” But he added: “It is something I do not tend to think about any more, something I want to put behind me.”

Thomas said during his school years he had come to the attention of the Prevent counter-radicalisation programme, which took him to see a female Holocaust survivor. Thomas said: “She told me she was evacuated from Germany to Britain and I couldn’t see that as being a Holocaust survivor, at the time.”

He said the photograph of him holding his child while wearing KKK robes was “just play”. He said: “They were not put up on some website or used to promote some agenda or ideology.”

Thomas said of chat groups where he had made antisemitic and racist remarks to other alleged National Action members: “That was entertaining to me at the time. It was funny at the time.”

Asked whether his parents had been “extremists or racists”, he said: “They were common racists.”

Thomas, who was twice turned down by the army because of an Asperger’s diagnosis, said his beliefs in white nationalism began at an early age and his racist views led to his expulsion from mainstream school aged 14.

Thomas said his paternal grandfather, from Derry in Northern Ireland, had “a positive view of Hitler and the Nazis” and used to deliver a “Hitler salute” when Thomas visited as a boy. He said his great-grandfather was a supporter of the British Union of Fascists.

Three other men who had been due to stand trial alongside the trio admitted being National Action members before the trial began.

Thomas’s friend Darren Fletcher, 28, of Wednesfield, West Midlands, Joel Wilmore, 24, of Stockport, Greater Manchester, and Nathan Pryke, 26, of March, Cambridgeshire, will be sentenced later.

Police believe the three found guilty on Monday, plus Fletcher, Wilmore and Pryke, and another two men who have also been convicted, made up a West Midlands National Action cell of at least eight people, which they have now dismantled.

Among them was a British army soldier, Mikko Vehvilainen, who was arrested at his army base in Wales in September 2017. Born in Finland, Vehvilainen was a 34-year-old lance corporal in the army who in April was sentenced to eight years’ imprisonment for membership of National Action.

The cell displayed hatred of Jews and Muslims in their encrypted online chats.

In one internet chat with other cell members, Vehvilainen told others: “These things will be decided when we have won the war against the Jews, deported the muds [Muslims], and cleansed our lands.”

DCS Matt Ward, of the West Midlands counter-terrorism unit, said: “Vehvilainen’s role typified the progress that National Action wanted: he was a noncommissioned officer in the British Army with access to young men who could be radicalised and recruited into the group. He was an incredibly dangerous individual and a key part of the National Action strategy.”

Also jailed for eight years after an earlier trial, which can only now be reported, was Alexander Deakin, who police believe was the regional coordinator. He was convicted of National Action membership, distributing extremist publications and two charges of possessing documents likely to be useful to a person preparing to commit an act of terrorism and distribution of a terrorist publication.

Ward said counter-terrorism investigators had to use all their powers and skill to catch and convict the cell, which was highly dangerous, adding: “These individuals were not simply racist fantasists, we now know they were a dangerous, well-structured organisation.

“Their aim was to spread neo-Nazi ideology by provoking a race war in the UK, and they had spent years acquiring the skills to carry this out. They had researched how to make explosives. They had gathered weapons. They had a clear structure to radicalise others. Unchecked, they would have inspired violence and spread hatred and fear across the West Midlands.

“Today’s convictions have dealt a significant blow to National Action. We have dismantled their Midlands chapter, but that doesn’t mean the threat they pose will go away.”

Ward said National Action followers would try to hide by changing the name of their group.

He said there was no evidence that those convicted and those who pleaded guilty were engaged in plotting an attack.