Duke once held a seat in Louisiana's state House of Representatives
Czech authorities have ordered a former Ku Klux Klan leader, David Duke, to leave the country.
The 59-year-old American was invited to the Czech Republic by a local far-right group and had planned to give lectures and promote a book.
But on Friday he was arrested and questioned by police on suspicion of denying the Holocaust, an offence under Czech law.
Mr Duke has not been charged, but was ordered to leave the country.
He has reportedly been given a deadline of midnight on Saturday.
His lawyer was quoted in local media as saying she would lodge a complaint against the police on his behalf.
The Czech interim prime minister-designate, Jan Fischer, appeared on Czech television to say the opinions expressed in Mr Duke's book were "simply unacceptable, incomprehensible".
David Duke is a former Grand Wizard of the notorious white supremacist Ku Klux Klan group. He once held a seat for the Louisiana state House of Representatives, and made an unsuccessful bid for the US presidency.