Staff at a Suffolk jail where nearly half the inmates are from ethnic minorities have been accused of racist behaviour in an official report.
The Chief Inspector of Prisons, Anne Owers, said there was a lack of awareness about minority groups among officers and prisoners at Highpoint.
Some staff used "derogatory language" to describe prisoners' race and nationality, the report said.
When questioned by inspectors some inmates claimed staff were racist.
The report said inspectors saw many black and Asian inmates who had a good relationship with staff at the 800-inmate prison, but many prisoners described officers as "culturally unaware".
Pressures on the jail had intensified because the number of inmates had expanded by a third since the end of 2004, but there had been no similar growth in work and education places at the jail, it added.
'Acted like bullies'
Only 54% of black and Asian prisoners said staff treated them with respect, compared with 81% of white prisoners surveyed by Ms Owers' team.
Among Muslim inmates the figures were even worse, with only 44% saying they were treated with respect and one in five saying they felt unsafe.
The report added: "Prisoners accepted that there was no general hostility from staff and recognised that some were helpful and approachable but also said some acted like bullies."
The document also highlighted "serious problems" with drugs at the prison near Newmarket, a category C jail which began life in 1938 as an RAF base.
One in four inmates said it was easy to get hold of drugs.
Ms Owers said: "At the time of inspection, Highpoint was not an effective training prison.
"The location, the lack of sufficient purposeful activity, the availability of drugs and the absence of a coherent resettlement strategy all contributed to undermining its core role."
She added: "Many of the prison's problems stem from the endemic and corrosive effects of population pressure - but tackling them will require both strong management and the active engagement of all the prison's staff."
Prison Service director general Phil Wheatley said: "The Chief Inspector accurately describes the very challenging operational problems facing the governor and her staff.
"They are working with specialist HQ staff to promote the race equality agenda at the prison.
"Plans are also well in advance to increase the amount of accredited activity available to prisoners."
He added that work was also being done to target drugs in the jail.
The report states that 45% of Highpoint's inmates are black or Asian.