It is not the first time Oakington has been criticised for its lack of facilities
Inspectors have delivered a damning report on an immigration detention centre, saying it has "lost direction and purpose" and inmates feel unsafe.
Relations between staff and inmates at Oakington Immigration Reception Centre, near Cambridge, was at an all-time low and the use of force up, they said.
Chief prison inspector Anne Owers said her findings were "disappointing."
The UK Border Agency said it took the report's concerns seriously and would consider its recommendations.
Ms Owers said: "This was a disappointing inspection of an establishment which seemed to have lost direction and purpose."
She blamed some of the apparent problems on uncertainty over the centre's future, which had been due to close in 2006 but has now had its life extended - possibly to 2012.
Ms Owers said the UK Border Agency - which runs Oakington on behalf of the Home Office - should publicly clarify the centre's future "as soon as possible."
She also called on Oakington's managers and staff to focus on running a "safe, supportive and purposeful environment" for the 328 detainees - all men facing removal from the UK.
According to the HM Chief Inspector of Prisons (HMCIP) report, half of the detainees felt unsafe.
The use of force had increased and was inadequately monitored.
Incidents of self-harm amongst detainees "had increased significantly during the previous 12 months."
Relationships between staff and detainees "had deteriorated significantly", with only 60% of detainees, compared to 89% at the last full inspection, saying most staff treated them with respect.
'Depressing and disturbing'
Ms Owers said: "These are significant and troubling slippages."
Her report describes the general attitude of staff as "distant and reactive."
It adds: "Neither staff nor managers appeared to take an interest in the individual circumstances and concerns of detainees.
"For example, they appeared unaware of the fact that they had been holding a Chinese man for nearly two years."
Accommodation at the centre lacked investment and was described as "tired and often uncomfortable."
Donna Covey, chief executive of the Refugee Council, which campaigns on behalf of refugees and asylum seekers, said the report's findings were "depressing and disturbing".
She said she was particularly concerned as up until recently the Refugee Council had support staff at the detention centre.
She said: "We have grave concerns about what is happening to people now that we are not there to provide that independent support.
"It is especially alarming that safety is such an issue - many of these people will be extremely vulnerable.
"Most detainees in this country now have no access to independent welfare support."
Ms Covey added: "It is unacceptable to lock people up simply for asking for safety in the UK, and then in a place which is clearly incapable of looking after them properly."
She also criticised the holding of children at such centres who she said "should never be detained".
The report did however give positive mention to security at the centre, which had improved and the number of escapes had reduced. Health care was described as "generally appropriate."
And any racist incidents that did occur were rare and were treated seriously.
Oakington, a former RAF base near Cambridge, opened in 2000. It has drawn fire in the past, particularly for the apparent ease with which detainees have managed to escape.
Earlier this year an official report branded it the second-worst detention centre in the country for its lack of facilities.
And the Archbishop of Canterbury, Dr Rowan Williams, has previously expressed concern at the treatment of detainees.
Responding to the HMCIP report, a UK Border Agency spokesperson said: "We take any concerns about the welfare of our detainees extremely seriously.
"Our removal centres play a vital role in enforcing immigration rules and we are determined to make sure they are well run, safe and secure.
"We are pleased that the report notes the improvements we have made and the good level of healthcare we provide to detainees.
"We will be considering the recommendations very carefully."