Child-sex offenders are not being adequately supervised at an immigration removal centre (IRC) near Heathrow Airport, a report has said.
Inspectors found one prisoner at Colnbrook IRC downloading “inappropriate content” in an internet room, as they carried out their checks.
Colnbrook IRC holds about 250 people.
The Home Office said it was working with Mitie – the company that manages Colnbrook – to ensure all prisoners were adequately supervised.
A report carried out by HM Inspectorate of Prisons (HMIP) in November and December, examined records of two detainees who had been convicted of child sex offences.
In both cases, a note was placed on the electronic records to the effect that visits should be supervised.
‘Grooming another detainee’
But inspectors found staff supervising visits were unaware the files should be checked.
The report said: “No other measures were taken to supervise these detainees, one of whom was subsequently found downloading inappropriate content in the internet room.
“He was banned from further use of the facility, but no further restrictions were placed on him.
“He was transferred to prison some days later, when an allegation was made that he was grooming another detainee.”
HMIP found there had been a “very significant increase” in self-harm at the facility, while staff and detainees told inspectors the availability of drugs was a problem.
Detainees had been held for an average of 75 days, including time spent in a previous place of detention.
Some had lived in the UK for many years. In one case, the Home Office was seeking to deport an adult ex-offender who had lived in the UK since the age of three months.
HMIP examined 12 cases in detail and concluded that in five the Home Office had “failed to act diligently or expeditiously”.
In reaction to the report a Home Office spokesman said: “We have always been clear that we expect the highest standards from detainee custody officers and others who work with detainees.
“We are working closely with Mitie to make sure that all high-risk detainees are properly supervised at all times.”