US military dog handlers at Baghdad's Abu Ghraib prison say they were ordered to use their animals to intimidate detainees, according to media reports.
Unmuzzled dogs were used to frighten prisoners at Abu Ghraib jail
They made the allegation in statements provided to military investigators, the Washington Post newspaper says.
The handlers also said the jail's top military intelligence officer had approved the tactic, the paper reports.
Pentagon officials have said abuses at Abu Ghraib were confined to a small group of military police soldiers.
But the Washington Post says the statements reinforce the view that there were two kinds of abuse at the jail - sexual humiliation and beatings at the hands of military police (MPs), and intimidation using dogs during interrogations under the auspices of military intelligence.
The MPs are accused of stripping, beating, humiliating and photographing detainees.
To date, seven MPs have been charged with abuses at the jail that do not include any incidents involving dogs.
The newspaper says that in their sworn statements, Sgts Michael Smith and Santos Cardona - US army dog handlers assigned to Abu Ghraib - told investigators that military intelligence personnel requested that they bring their unmuzzled dogs to prison interrogation sites on several occasions in December and January.
They said Col Thomas Pappas, who was in charge of military intelligence at the prison, told both of them that the use of dogs in interrogations had been approved, according to the paper.
The Post also quotes a military intelligence interrogator's statement as saying that two dog handlers at Abu Ghraib were competing to see how many detainees they could make involuntarily urinate out of fear of the dogs.
In his statement, Specialist John Harold Ketzer, a military intelligence interrogator, reportedly says saw a dog team corner two male prisoners against a wall, one prisoner hiding behind the other and screaming.
"When I asked what was going on in the cell, the handler stated that he was just scaring them, and that he and another of the handlers was having a contest to see how many detainees they could get to urinate on themselves," he is quoted as saying.
Elisa Massimino, a director of New York-based Human Rights First, said using dogs to frighten and intimidate prisoners violated the Geneva Convention, and was also a violation of US policy as stated in the army field manual.