Ousted Iraqi leader Saddam Hussein and three of his co-defendants on trial for crimes against humanity have launched a new hunger strike, the US military said.

Ousted Iraqi leader Saddam Hussein listens during his trial in Baghdad in June 2006. Saddam and three of his co-defendants on trial for crimes against humanity have launched a new hunger strike. [AFP\File]

"Saddam Hussein and his three co-defendants have now refused meals since their evening meal on July 7," said US spokesman Lieutenant Colonel Keir Kevin Curry on Thursday.

Saddam, his former secret police chief Barzan al-Tikriti, vice president Taha Yassin Ramadan and head of the former revolutionary court Awad al-Bandar, are all on trial over a crackdown against a Shiite village following an assassination attempt against the former Iraqi leader in 1982.

"All are apparently protesting the Iraqi High Tribunal procedures and security for the defense attorneys," added Curry.

"Saddam Hussein is drinking coffee with sugar and water with nutrients," he said, adding that all the defendants were in good health and receiving additional medical care.

Issam al-Ghazzawi, one of Saddam's lawyers, told AFP from Amman that the hunger strike was because "the demands of the defense committee for the protection of the lawyers and the guarantees for a fair trial had not been met."

On June 21, Khamis al-Obeidi, a member of Saddam's defense team, was murdered in Baghdad and since then, the four major defendants and their lawyers have been boycotting the trial.

Hearings are due to resume on July 24 and a verdict is expected next month.

Since his December 2003 capture, Saddam and other high-level regime officials have gone on brief hunger strikes a number of times, the longest, according to his lawyers, lasting 11 days in February.