Papua New Guinea police systematically beat detainees, cripple those suspected of serious crimes and sexually assault female prisoners, a United Nations report said Tuesday. After spending almost two weeks touring the impoverished Pacific island country, the UN's Special Rapporteur on torture Manfred Nowak said police often brutally beat detainees with car fan belts, gun butts, iron rods and stones. 'I found systematic beatings of detainees upon arrest or within the first hours of detention, including during interrogation,' Nowak said in a statement on his preliminary findings issued in Port Moresby. 'Very often beatings are inflicted by the police as a form of punishment of suspects, reflecting complete disrespect for the presumption of innocence and the dignity of persons suspected of crimes.' Nowak, who carried out unannounced visits to police lock-ups and jails and conducted confidential interviews with detainees, said he was disturbed by some of what he heard. 'I am very concerned about the practice of the police to deliberately disable persons suspected of serious crimes and those who escape from detention,' he said. In jails, those who tried to escape were tortured upon recapture as a standard practice, he said. This included brutal beatings with machetes or rifle butts, shooting the legs and feet of detainees at close range and cutting their tendons with knives and axes to cripple them. Women were particularly vulnerable while in police custody, with many allegations of sexual abuse, Nowak said. 'Some officers also appear to frequently arrest women for minor offences with the intention of sexually abusing them,' Nowak said. 'As a punishment, some women were also threatened or were placed in cells with male detainees for a night, where they were subjected to collective rape by the other detainees.' Nowak said officers with the Royal Papua New Guinea Constabulary, the regular police force, were often unable to enforce the law due to insufficient human and financial resources, corruption, unprofessionalism and a lack of political will. 