Former Ku Klux Klan leader David Duke – who announced plans to visit Ireland last week to campaign against immigration – has been arrested in the Czech Republic on suspicion of denying the Holocaust.

Duke announced on the Irish White Nationalist Party website Stormfront last week that he intended to travel here: "I am thinking about visiting Ireland, doing some research for my new book and am looking forward to meeting with some Irish patriots in the land of my ancestors."

But last Friday, Duke travelled to Prague to deliver a lecture at a university course on extremism. The university cancelled his appearance because they suspected neo-Nazis planned to attend.

Later that evening, police arrested and questioned him on suspicion of denying the Holocaust, a legal offence under Czech law. Although he was not formally charged, Duke has now been banned from the Czech Republic.

It is unlikely that Duke's recent brush with law will prevent him from visiting Ireland. On Stormfront's Irish website, he asked his supporters in Ireland to contact him and enquired about the possibility of sponsorship.

A former Grand Wizard of the Knights of the Ku Klux Klan, Duke joined the Klan aged 17 and is best known for modernising the movement, bringing about the change of title from Grand Wizard to National Director and replacing the white robes with business suits.

A controversial figure, he was jailed in 2003 for 15 months for tax fraud and fined over €7,000. He pleaded guilty to defrauding thousands of his own supporters.