A self-declared "king" of Germany and three of his senior "subjects" have been arrested and their group banned for attempting to overthrow the state.

Peter Fitzek, 59, was among those arrested in morning raids across seven states on Tuesday, which involved about 800 security personnel.

The government banned their group, the Reichsbürger, or "citizens of the Reich", which seeks to establish the Königreich Deutschland, or "Kingdom of Germany".

Alexander Dobrindt, German's interior minister, accused the group of attempting to "undermine the rule of law" by creating an alternative state and spreading "antisemitic conspiracy narratives to back up their supposed claim to authority".

His ministry announced the dissolution of the group, and accused it of financing itself through "economic criminal structures".

Fitzek, a former chef and karate instructor, calls himself "king" and identified himself to judges as "Peter the First" in a previous court case.

He had himself crowned in 2012 while dressed in ermine robes and brandishing a medieval sword. Since then he has been buying land and property across Germany.

Reichsbürgers have their own currency, flag and ID cards, and want to set up separate banking and health systems.

Fitzek claims to have thousands of followers - or "subjects".

In an interview with the BBC in 2022 he denied having any violent intentions, but also described the German state as "destructive and sick".

"I have no interest in being part of this fascist and satanic system," he told the BBC's Jenny Hill, when she visited his "kingdom" in eastern Germany.

Fitzek has repeatedly clashed with the authorities and refused to abide by German laws, often in what appears to be in a publicity-seeking manner.

He has previously been jailed for repeatedly driving without a licence, following a decision to hand his back in a symbolic rejection of the law. At the end of one trial session, Fitzek was seen getting into his car in front of the court and driving off.

Fitzek is one of around 25,000 Reichsbürger in Germany. Numbers have been growing over the last few years.

Many are right-wing extremists who peddle racist and antisemitic conspiracy theories. They refuse to recognise the authority of security forces and many possess illegal arms, which has led to shoot-outs with police. Officials say that around 2,500 are potentially violent and that 1,350 are classed as right-wing extremists.

In 2022 dozens of people were arrested, many of them Reichsbürger, for plotting to overthrow the German government in Berlin. They were accused of planning a violent coup, which included kidnapping the health minister, to create "civil war conditions" to bring down German democracy.

In the past, Reichsbürger were often dismissed as eccentric cranks because of their outlandish ideas.

But as the far right has grown in strength politically in Germany over the last decade, officials now see them as a serious threat.

The federal prosecutor's office in Karlsruhe said Fitzek was arrested along with three other suspected ringleaders of the group, which it classified as a criminal organisation.

As the "so-called supreme sovereign", Fitzek had "control and decision-making power in all key areas", the office said.

"The 'Kingdom of Germany' considers itself a sovereign state within the meaning of international law and strives to extend its claimed 'national territory' to the borders of the German Empire of 1871," it added in a statement.