US officials yesterday denounced the acquittal of the brother of the UAE President who had been tried on charges of torturing an Afghan trader in 2004.

"It's not a credible verdict," a senior official said, asking to remain anonymous, after the ruling handed down on Sunday on Sheikh Issa bin Zayed al-Nahayan by an Emirati court.

The 40-year-old sheikh is the brother of the President of the United Arab Emirates and the ruler of oil-rich Abu Dhabi, Sheikh Khalifa bin Zayed al-Nahayan. The UAE is a key regional ally of the US.

Sheikh Issa was acquitted by the court "after establishing he was not responsible" for the torture of the Afghan merchant in 2004 because he was under the influence of medication at the time, his lawyer Habib al-Mulla said.

But five co-defendants, including two Americans, were convicted.