Muntazer al-Zaidi had been due to hold a press conference in front of the Iraqi capital's Abu Hanifa mosque in the mostly-Sunni district of Adhamiyah when an Iraqi army unit took him away.

"I have orders for you to come with me," an army colonel told Zaidi, who initially refused, demanding to see a written arrest warrant. He was eventually led into an army pick-up truck along with his brother Durgan.

Durgan al-Zaidi told AFP before the news conference that his brother intended to add his voice to calls for a major protest in Baghdad tomorrow.

The journalist shot to international notoriety for hurling both his shoes at Bush during a December 2008 press conference in Baghdad, and was eventually sentenced to three years in prison for assaulting a head of state.

That was reduced to one year on appeal, and his sentence was cut further for good behaviour. Zaidi alleged he suffered electric shocks and simulated drowning while in custody