* Evidence is classified

* Hurts U.S. advocacy of press freedom

* Family waits for son's return

BAGHDAD, Sept 2 (Reuters) - On Sept. 2, 2008, U.S. and Iraqi troops smashed in the doors of Iraqi journalist Ibrahim Jassam's home, shouting "freeze" and holding back snarling dogs before they hauled him off into the night in his underwear.

A year later, neither Jassam and his family nor global news agency Reuters, which employed him as a freelance TV cameraman and photographer, have been told exactly why he has been detained for all this time by U.S. military forces in Iraq.

The evidence against Jassam is classified, but the accusations have to do with "activities with insurgents", said Lt. Col. Pat Johnson, a spokeswoman for the U.S. military in Iraq. The term "insurgents" in Iraq generally refers to Sunni Islamist groups, like al Qaeda. Jassam is a Shi'ite Muslim.

"In a year of trying to get specifics, we've heard only vague and undefined accusations - to me this is unacceptable," said David Schlesinger, editor in chief of Reuters, the news arm of international media and information provider Thomson Reuters.

"It is only right and fair that any specific accusation against a journalist should be aired publicly and dealt with fairly and swiftly, with the journalist having the right to defend himself properly."

Jassam, who is being held in a prison camp built in the desert on the Iraq-Kuwait border, will eventually be released.

Under a U.S.-Iraqi security pact, called a Status of Forces Agreement, the U.S. military must hand over the thousands of Iraqis it still has in its custody as Iraq gradually regains its sovereignty more than six years after the U.S.-led invasion.

Those facing Iraqi charges will be tried; the rest freed.

The Iraqi Central Criminal Court already ruled last November there was no case against Jassam. [ID:nLU123205] [ID:nL9585447]

But the U.S. military says it considers Jassam a security threat to Iraq. It says that under the security agreement, it is entitled to hold Jassam as long as possible.

"Though we appreciate the decision of the Central Criminal Court of Iraq in the Ibrahim Jassam case, their decision does not negate the intelligence information that currently lists him as a threat to Iraqi security and stability," Johnson said.

'INCONSISTENT WITH SPIRIT OF ACCORD'

Reuters argues the U.S. army is misinterpreting its remit.

"Ibrahim Jassam has never been charged by the U.S. military or the Iraqi authorities, and has never had a single piece of evidence or even a specific allegation of wrongdoing presented to him," said Thomson Reuters deputy general counsel Thomas Kim.

"We believe this is not consistent with the spirit behind either the Status of Forces Agreement ... or the Rule of Law." The U.S. military detained many Iraqi journalists during the sectarian slaughter and insurgency unleashed by the 2003 invasion. None have been known to have been charged.

Journalists rights groups say U.S. forces may be misinterpreting legitimate journalistic activities in war zones. Taking pictures of Shi'ite militiamen battling U.S. troops, for example, might look like enemy propaganda to a U.S. soldier.

"The year-long detention of Ibrahim Jassam without charge or due process is not only unjust it also undermines the ability of the U.S. government to effectively advocate for press freedom around the world," said Joel Simon of the New York-based Committee to Protect Journalists. [ID:nN10320526]

The U.S. military said it expected all high security threat detainees to go before an Iraqi judge starting in December 2009. The intelligence information against Jassam will be aired then.

Meanwhile, Jassam's mother, Fadhila Alwan, is waiting impatiently to welcome him back to the family home in Mahmudiya, 30 km (20 miles) south of Baghdad, so she can see her son marry.

Six months before Jassam's arrest, another teenage son was killed by what the family says was fire from a U.S. helicopter while he was crossing a street to buy bread at a bakery.

Mahmudiya, in the "Triangle of Death," was a violent town, in the grip of Shi'ite militias, and gunbattles were common. The U.S. military has not revealed details about the arrest, but Alwan said when the soldiers came at 1 a.m., the family was sleeping on the roof to escape the heat of late summer.

'YOU WOULD WEEP AND BEAT YOUR HEAD'

The Iraqi soldiers were abusive and cruel, pushing Jassam's elderly father to the ground before their U.S. counterparts stopped them, she said. They smashed every door in the house.

"My three sons there, including Ibrahim, were tied by plastic ropes and soldiers forced them to lay down with their faces on the ground. One of the Americans was looking at a small photo strapped to his forearm, and then he ordered Iraqi soldiers to take Ibrahim downstairs," she said.

"Ibrahim told them he was a journalist and hadn't done anything wrong. The Iraqi soldiers told him to shut his mouth." They took Jassam's cameras and computer hard drive away.

His sister, Layla Jassam, said she asked the Iraqi soldiers where they were taking Jassam. "If you knew where we were taking him you would weep and beat your head," one replied, she said.

The family says it has been hard not knowing anything.

"We asked his lawyer, we asked military officers, we've asked all the officials we meet, but not one of them knew why he's been in jail for a whole year," said Alwan. (Additional reporting by Ahmed Rasheed; Editing by Missy Ryan and Jon Hemming)