Controversy is raging in Iraq over the alleged rape of a young Sunni Muslim woman by police.
By Roger Hardy
BBC Middle East analyst
Following her appearance on Monday on al-Jazeera TV channel, Prime Minister Nouri Maliki's office said the medical evidence showed she had not been sexually assaulted.
The woman says she was raped by three police officers
It described the woman as a liar and a criminal and said the three policemen should be commended.
But Sunni politicians are accusing the Shia-dominated government of a cover-up.
Who to believe? The facts are now blurred in a thick cloud of sectarian charge and counter-charge.
The 20-year-old married Sunni woman says she was taken from her home in Baghdad to a police station, where she was accused of helping insurgents - and then raped by three policemen.
The Baghdad police are predominantly Shia.
She was later treated at Ibn Sina hospital, which is run by the US military in the heavily fortified Green Zone.
In conservative Muslim societies, rape carries a special stigma. Victims seldom speak out for fear of shaming their families
According to a document released by Mr Maliki's office, US doctors found no evidence of rape.
However, US officials in Baghdad - clearly feeling themselves caught in the middle of this bitter controversy - say privacy rules prevent them from commenting.
The New York Times reports that an Iraqi nurse who says she treated the woman saw signs of sexual and physical assault.
Believing the worst
But whatever the facts, the story has now taken on a life of its own.
Sunni politicians are outraged by the speed with which the prime minister dismissed the woman's allegation.
Prisoners at Abu Ghraib made allegations of sexual humiliation
Having often alleged brutal treatment by Baghdad's mainly Shia police, Sunnis are ready to believe the worst.
The prime minister continues to insist the whole affair is a politically motivated fabrication.
On Wednesday he fired a senior Sunni official who had issued a statement describing the alleged rape as a "horrific crime" and calling for an international investigation.
The official, Ahmed Abdul-Ghafour Samarrai, was head of the Sunni Endowments, a body responsible for the care of Sunni mosques and shrines.
In conservative Muslim societies, rape carries a special stigma.
Victims seldom speak out for fear of shaming their families.
The allegations of abuse by US guards at the Abu Ghraib prison in Baghdad were all the more shocking because they included sexual humiliation.
Iraqis imprisoned during the Saddam Hussein regime have alleged they were sexually abused or forced to watch the abuse of a close relative.