The US military is investigating a second case of alleged prisoner abuse to come to light in Afghanistan within the past week, a spokesman said. The US military is already investigating allegations from a former Afghan police officer that he was assaulted, sexually taunted and deprived of sleep while in detention. The US-led coalition in Afghanistan was notified Thursday of "another allegation of detainee abuse," spokesman Lieutenant Colonel Tucker Mansager told a press briefing in Kabul. "There is an ongoing investigation into these allegations. As we have said before, we take all these allegations very seriously and upon notification we immediately began an investigation," he said. "We are determined to find out all the facts and get to the bottom of the allegations." Mansager did not elaborate on the latest allegations but said that the complaint had not come from the detainee, who was taken into custody in 2003 and later released, but from a "second source." He did not give any further details on the prisoner. "Because the US army's criminal investigative division is conducting the investigation, it would not be good right now for me to comment on the investigation because we do not want to prejudice the investigators and their outcome in any way shape or form," he said. "The investigation will be thorough and complete and when it draws its conclusions appropriate actions will be taken against anybody who may be proved to have done something wrong." On Wednesday the United States said it was investigating claims of abuse from an Afghan held for between 40 and 45 days and later released. The man, a former police colonel, told AFP that he had been beaten, stoned and asked which animal he would like to have sex with while in US custody in the southeastern city of Gardez and in southern Kandahar. Allegations of abuse of prisoners in Afghanistan emerged following shocking pictures of US soldiers abusing Iraqi detainees in Baghdad. Despite strong calls from rights organisations to be allowed to visit detention facilities in Afghanistan, Mansager said there would be no change to the US's policy of only allowing officials with the International Committee of the Red Cross (ICRC) to visit detainees. So far the ICRC had only visited the Bagram facility, he said. **PHOTO CAPTION*** Former Afghan police colonel Khwaja Sayed Nabi Siddiqi shows how he was shackled as a prisoner of US forces as he conducts an interview in his home in Gardez, last week. (AFP)