BAGHDAD - Iraqi journalist Muntazer al-Zaidi, who gained instant international fame when he threw his shoes at US President George W. Bush, goes on trial in Baghdad Wednesday and faces a possible 15-year prison term.

The 29-year-old journalist who works for Al-Baghdadia television channel is being hauled before a court on charges of "aggression against a foreign head of state during an official visit."

The Baghdad court could choose to dismiss the charge or alter it to a lesser one of "attempted aggression" which carries a prison term of one to five years.

Zaidi threw his shoes at Bush during the US president's farewell visit to Iraq on December 14, an action considered a grave insult in the Arab world.

He also insulted the American president, shouting: "It is the farewell kiss, you dog."

His action was hailed across the Arab world as an ideal parting gift to an unpopular US president.

Zaidi will be tried by the Central Criminal Court of Iraq, responsible for terrorism cases and located in the Green Zone, the heavily protected area of Baghdad where the Iraqi government and some Western embassies are located.

The court which comprises three judges will decide whether to make a decision at the end of the first session or at a later date.

"The trial will be public and open to the press," court spokesman Abdel Sattar Beyraqdar told AFP.

"The court will decide on the trial's length and it will decide whether to take one day or more," Beyraqdar added.

Zaidi's lawyer, Dhiya al-Saadi, told AFP that he had demanded the trial be cancelled.

"Our appeal is based on the fact that Zaidi simply expressed his rejection of the occupation and the policy of repression against the Iraqis. Zaidi's act falls within the framework of freedom of expression," his lawyer said.

"If the court rejects our request for cancellation, the defence will to appeal to a higher court," Saadi added.

Investigating judge Dhiya al-Kenani rejected allegations by the journalist's family that he had been tortured in custody, charges that were levelled after his brother was allowed to visit him in prison.

Kenani, however, confirmed that Zaidi's lawyer had lodged a complaint over his treatment and that a letter would be sent to the office of Prime Minister Nuri al-Maliki to request that security guards be brought to justice.

One of Zaidi's brothers, Uday, told AFP previously that he had been able to visit him in custody on December 21.

"I met my brother for around an hour. He has been tortured while in detention for 36 hours continuously. He has been hit with iron rods and cables," Uday said.

"He was forced to sign a statement confessing to receiving money from different groups and saying that he did not throw his shoes for the honour of Iraq," Uday said.

"But Muntazer said I will not apologise for what I did -- not now, not ever."

Maliki's office said that the premier had received a letter signed by Zaidi alleging third party involvement in his protest.

"Muntazer al-Zaidi has expressed regret in a letter I received from him in which he revealed that an individual persuaded him to commit this action and that this person is well-known for beheading people," it quoted Maliki as saying.

The allusion was clearly to insurgent groups opposed to his US-backed government that have executed captives in the past, but it was unclear precisely which individual Maliki was referring to.

The judge dismissed the family's torture allegations.

"Muntazer's brother is lying, because there are only bruises on Muntazer's face that he received during the arrest and they are small ones," Kenani told AFP.

Al-Zaidi missed Bush, who ducked the throws, but Iraqi and US security officials grappled with him and hustled him off while the US president tried to joke his way out of the incident.

The incident inspired a British student, Alex Tew, to create a "Sock and Awe" (www.sockandawe.com) shoe-throwing site on which anyone can take a swipe at the US leader on the Internet.

A White House spokesman reiterated the US position that it is up to Iraq to decide the fate of Zaidi.