The officers have been suspended on full pay for nearly two years while almost pounds 5m of public money has been spent during an investigation into the allegations, which involve a total of about pounds 10,000. No one has yet been charged.
They have been allowed to take additional paid jobs including training airport staff in baggage X-rays, selling corporate hospitality and working as closed-circuit television operators for private security companies.
The officers, under investigation by West Yorkshire Police, were high- flyers handpicked to attend prison colleges in Wakefield, Preston and Doncaster for training in new security procedures.
They are accused of making expenses claims for hotel stays and travel that never took place involving sums ranging from pounds 6 to several hundred pounds.
The investigation stemmed from the arrest of Keith Mather, a senior prison officer jailed for 16 months in March after admitting deception charges involving a total of pounds 17,000.
Mather made claims to detectives that expenses fraud was widespread, triggering the current investigation.
The suspended officers deny wrongdoing and claim they are being victimised after the discovery of widespread corruption within the service.
The Independent has learned that one officer who accepted a police caution for a false claim, has since been promoted to deputy governor. Another officer has been returned to post despite admitting to claiming lodging allowance while on holiday.
Last night one of those suspended since November 1996 said: "We are being victimised to set an example while others have been protected. It's despicable and reprehensible."
Four of the suspended officers have recently retired and four have resigned, leaving 34 still suspended.
Among those arrested was a senior prison officer based at the Prison Service College in Wakefield, who admitted claiming overnight accommodation while staying with a friend.
He was given a police caution and co-operated with detectives in their investigation into other claims. Prison chiefs felt that the matter should be dealt with on an "informal basis" and asked him to repay pounds 34 overclaimed.
He has since been promoted to deputy governor.
The West Yorkshire police inquiry has inspired separate fraud investigations at jails in the Midlands and the South-east.
Four officers have been sacked at High Down and Downview prisons in Surrey, which now involves allegations against nearly 30 members of staff. Physical education instructor Julian Henton, one of the sacked officers, later received pounds 10,245 from the government for unfair dismissal.
He was given a police caution for claiming an extra pounds 39.70 for bogus accommodation expenses.
Mr Henton, 36, an Army Falklands veteran with eight years' experience in the prison service, said: "We did something wrong but we didn't do it callously. Now I have lost everything and I'm not sure if anyone will ever employ me again."
The Prison Service said there was "no evidence" that fraud was widespread throughout the service. A spokesman said that all allegations of fraudulent behaviour on the part of staff were "investigated thoroughly".
He said: "No member of staff will be accorded special treatment on account of their rank, position or any other factor."Reuse content