The suit is being brought on behalf of 11 former Iraqi detainees of the notorious Abu Ghraib prison near Baghdad and one Saudi currently being held at the US prison in Guantanamo Bay, Cuba.

The suit was filed to Germany's federal prosecutor Monika Harms at her offices in the western German city of Karlsruhe, said Hannes Honecker, the secretary-general of the Germany-based Republican Attorneys' Association.

German law allows the pursuit of war crimes cases regardless of where they originate in the world or the nationality of person being tried.

Second attempt to file lawsuit in Germany

A similar attempt to prosecute Rumsfeld in Germany was rejected two years ago, but the German lawyer representing the detainees, Wolfgang Kaleck, told a press conference in Berlin he was confident the complaint would be followed through on this occasion.

"We failed two years ago because there was an ongoing investigation in the United States, but it is now clear that there is no chance of prosecuting high-ranking officials in the US," Kaleck told a press conference in Berlin called to present the complaint.

"We are not expecting that Rumsfeld will appear in a court, but we are hoping investigators will begin looking into the case," he said. "If we fail here, we will try in France, or in Spain. We want to show that there will be no safe haven anywhere in the world for him."

The lawyer for the Guantanamo detainee, Mohammed al-Qahtani, claims Rumsfeld approved special "tactics" when he failed to break under interrogation. The measures included sleep deprivation and a ban on praying, lawyer Gitanjali Gutierrez said.

"This is not just allegations, it is supported by government documentation," she added.

The complaint asks Harms to open an investigation and, ultimately, a criminal prosecution that will look into the responsibility of high-ranking US officials for allegedly authorizing war crimes in the context of the war on terror, according to the lawyers.

Rumsfeld resigned last week after Republicans lost control of the US Congress to the opposition Democrats in mid-term elections seen as a referendum on the war in Iraq.

Former Abu Ghraib commander as defense witness

The groups have former US Army Brigadier General Janis Karpinski, who commanded 17 US-run jails in Iraq including Abu Ghraib, as a witness on their behalf.

"What I see as my obligation is to provide the truth about what I saw and what I experienced in Iraq," Karpinski said at a press conference. "When I was getting too close to what was happening they took me out of the equation -- they removed Abu Ghraib from my control.

"Hopefully my testimony will stop this sort of thing ever happening again. I feel we have an obligation to the rest of the world because if the US does something it gives permission to the

rest of the world, but it doesn't mean it is right," Karpinski added.

Former White House counsel and current Attorney General Alberto Gonzales, former director of the Central Intelligence Agency George Tenet, and other high-ranking US officials are also charged in the complaint.

Other groups involved in the suit include the US-based Center for Constitutional Rights and the Paris-based International Federation for Human Rights.

The Abu Ghraib scandal erupted in 2004 after photographs were leaked to the press showing US guards mistreating and sexually humiliating prisoners. Some pictures showed naked inmates cowering in front of unmuzzled dogs.