An officer at Lindholme immigration removal centre near Doncaster has been sacked over allegations of racism.
The removal centre is part of the Lindholme Prison complex
He regularly referred to North African detainees as "donkeys" and made animal sounds, a report by the Home Office's Border & Immigration Agency says.
When asked about the claims, the deputy centre manager said racist behaviour would not be tolerated and the officer had recently been dismissed.
Detainees felt racist attitudes were common among officers at the centre.
An audit of immigration removal centres was commissioned after an inquiry by Prisons and Probation Ombudsman Stephen Shaw into the 2005 BBC programme Detention Undercover that made allegations of racism by staff towards detainees.
Visits to the immigration removals centres were conducted by Focus Consultancy between 30 January and 9 March 2007.
The Borders & Immigration Agency said its findings "did not support serious allegations of racism or mistreatment of detainees but highlighted areas for improvement with regards to race relations".
The agency's chief executive, Lin Homer, said: "Removing people from the UK, where they have no legal right to be here, is about fairness and enforcing the rules.
"However it is important to treat those being detained with courtesy and dignity, and to effect their removal in the same spirit.
"The Border and Immigration Agency takes any allegation of abuse or misconduct very seriously which is why we commissioned this report."
More training needed
The report into Lindholme said: "The relationship between staff and detainees is good. Very few detainees reported any negativity in their day-to-day interactions with staff.
"However, many detainees commented on a named member of staff, whose behaviour towards them was racist.
"The staff member in question regularly referred to detainees as 'Algerian, Moroccan or Egyptian donkey', accompanied by full animal sounds, depending on their country of origin.
"Other statements made by the same officer were 'Donkeys, go back to your country' and 'Keep the crime in your country'.
"The detainees interviewed felt that this attitude was common amongst officers, but only one particular officer vocalised his views."
It said that although all staff received race relations training, the centre manager must develop a programme for the additional training.