But the prison officers' union rejected the accusations, saying Holloway was no worse than any other jail.

Sir David Ramsbotham: prisons must be safe for prisoners and staff (2'17")

Sir David Ramsbotham said: "We were told, we believe with some justification, that junior staff were being bullied by some of their more senior colleagues.

"It was suggested to us that some managers did not understand the underlying sexual element to some of the bullying which took place."

Sir David: bullying must be dealt with

Sir David said no disciplinary action was taken but staff were spoken to by their line managers.

New staff had been drafted into the women's jail as more experienced staff were transferred to new prisons.

He said: "There has been a huge turnaround of staff. We feel that Holloway now needs a period of stability."

Sir David added: "There is an anti-bullying strategy in place for prisoners and there needs to be one for staff. Both need to feel there is a mechanism so that if there are complaints, they will be dealt with."

Prison governor Mike Sheldrick admitted bullying of staff had become a problem.

"Bullying in the workplace is an issue that is very common - and prisons are no different to other places of work," he told a press conference at the jail.

"Managers have to be aware of pressures that can be placed on staff."

No 'particular problem'

But a spokesman for the Prison Officers Association (POA) said sexual harassment and bullying among staff could be a problem in prisons as it could be in other workplaces.

"I am not aware of Holloway coming to the attention of the union as having a particular problem."

Sir David did praise the jail for the improvements made since 1995 when he withdrew his team in disgust at conditions.

He added that he hoped the recent appointment of a national assistant director for women, Linda Jones, would mean women behind bars received the special treatment they needed.

The Prison Service Director General, Richard Tilt, said an extra £500,000 was being spent to improve life for inmates in Holloway and to provide "offending behaviour" courses.