Officials at an immigration removal centre were too dismissive of reports from detainees claiming to be victims of torture, inspectors have said.
The so-called Rule 35 reports at Dover immigration removal centre in Kent were poor, "often hand-written and difficult to read and did not contain photographs or body maps", the Chief Inspector of Prisons Nick Hardwick said.
"Cases involving torture described scarring but lacked photographs or body maps," he said.
"There were no judgments on whether scarring was consistent with the alleged method of abuse. For example, in a case where the detainee claimed to have been shot, there was no judgment on whether the scars were consistent with gunshot wounds."
Calling for the troubled UK Border Agency (UKBA) to urgently improve its response to such claims, Mr Hardwick said the replies were "dismissive and none had led to the release of a detainee".
"In one case, despite a report by a health care professional which described scarring, the reply stated: 'There is no medical evidence to support your contentions...
"'Were it even vaguely credible that you were ill-treated in the manner described, it is considered that you would have raised this at the earliest opportunity.'"
Overall, the inspectors found the centre had improved in April since it was last inspected in May last year.
But Mr Hardwick added: "The two key areas that still needed to be addressed were the poor quality of information provided by UKBA to detainees and the lack of adequate support to help detainees prepare for release or removal."
Keith Best, chief executive of campaign group Freedom from Torture, said: "When it comes to the UKBA's efforts to fix the chronically dysfunctional rule 35 process, HMIP's verdict of 'prompt but dismissive' says it all.
"The UKBA has ploughed its energies into speeding up processing of rule 35 forms but these efforts have come to nought for survivors of torture who remain in detention because case owners dismiss the medical evidence in these reports out of hand.
"The example of the case owner flatly rejecting the possibility that someone would make a late disclosure of torture involving anal rape is sadly very typical of the cases we see on a regular basis."
He went on: "This inspectorate has repeatedly castigated the UKBA for frustrating the operation of rule 35.
"Parliament, which created rule 35, must take further action to hold the UKBA to account and ensure rule 35 is a meaningful safeguard for torture survivors wrongly detained in these detention centres."