Reporters Without Borders has written to tell US Defence Secretary Donald Rumsfeld that it is "appalled" by the revelations from Reuters about the torture at the hands of the US Army of three of its employees in Iraq.

The international press freedom organisation also condemned the Pentagon's "lax attitude and total lack of openness in the case. Unsatisfactory replies and the obvious failure to hold any effective investigation, despite repeated requests from the British news agency, do no reflect well on the American government," it said.

"The accounts given by the Reuters journalists are overwhelming. The facts reported are extremely serious. However the US Army, apparently believing itself above the law, for months have not deemed it necessary to interview the three victims" said the organisation.

"We ask you this time to react with the real integrity and through a proper investigation of these very serious accusations, including those made by a cameraman with al-Jazeera, Hassan Saleh, who has also reported that he was tortured at Abu Ghraib prison in November 2003."

"The investigations must be reopened, not with the aim of clearing the army but with the intention of shedding light on these allegations of torture and to punish those responsible," concluded Reporters Without Borders.

Three Reuters staff have reported that they were beaten and exposed to humiliating and degrading treatment of a sexual and religious nature during their detention in a US military camp near Fallujah, in January 2004. The three Iraqis, two journalists and their driver, recounted their ordeal to Reuters when they were released on 5 January. But they only decided to go public after the US Army challenged all the evidence of maltreatment and the media had revealed the practice of torture in Abu Ghraib prison.

In a letter dated 5 March, but only received by Reuters two days ago,. Lt-Gen. Ricardo Sanchez, Commander of US ground forces in Iraq said he was convinced that the investigation had been "thorough and objective". In the light of the latest facts about maltreatment of Iraqi detainees in Abu Ghraib prison, Reuters Global Managing Editor, David Schlesinger, recently urged the Pentagon to review its previous findings.

The maltreatment took place at a military base near Fallujah, Forward Operating Base Volturno. Cameraman Salem Ureibi, Fallujah-based freelance Ahmad Mohammad Hussein Al-Badrani and driver Sattar Jabar Al-Badrani, were arrested on 2 January 2004 while they were covering a US Army helicopter accident near Fallujah. All three were released without charge on 5 January.

"When I saw the Abu Ghraib photographs, I wept," Ureibi said. "I saw they had suffered like we had."

A summary of the investigation conducted by the 82nd Airborne Division, dated 28 January and provided to Reuters said : "No specific incidents of abuse were found". It said soldiers responsible for the detainees were interviewed under oath and "none admit or report having knowledge of physical abuse or torture". The US Army never interviewed the three Reuters employees.

Reporters Without Borders also urged the Pentagon to carry out a separate investigation into the conditions of detention of Hassan Saleh, aged 33, a cameraman with the Qatari-based al-Jazeera. According to his account, carried in several media including British daily The Guardian and the US magazine The Nation, he was maltreated on several occasions in the Abu Ghraib prison.

The US Army arrested Saleh on 3 November 2003, near Baquba, about 40 kilometres north of Baghdad, while he was covering a bomb attack that had just occurred against an American convoy. His interrogators accused him of having advance knowledge of the explosion.

Saleh described how he was first driven to the international airport in Baghdad then to Tikrit, before being taken to Abu Ghraib prison in Baghdad where he was stripped, beaten and insulted, soldiers calling him "al-Jazeera", "boy" and "whore". During his detention he was forced to remain standing naked for 11 hours with this head in a bag. He was then beaten, dressed in a red outfit covered in vomit then interrogated by two Americans in plain clothes. They accused al-Jazeera of working with terrorists.