Kilmarnock is the only privately-run prison in Scotland

An undercover reporter for Real Story filmed officers turning a blind eye to the use of drugs and alcohol.

He also found some prisoners on suicide watch were not checked regularly.

Scottish Prison Service spokesman Tom Fox voiced "real concerns" about the allegations - but stressed the evidence had not been shared with the SPS.

Premier Prisons, which runs the jail, has launched an investigation and three officers have been suspended from normal duties.

I think it's important that the public get the service that they're entitled to expect Tom Fox Scottish Prison Service spokesman

Mr Fox told BBC Radio's Good Morning Scotland programme: "I am confident that the company will take appropriate action against individuals who have behaved improperly but they cannot do that until they've seen all of the evidence."

He said that prison staff sometimes did not reach the high standards which were expected.

"I think it's important that the public get the service that they're entitled to expect and that people who, after all, are being paid by public money reach the highest standards of behaviour," he said.

"I don't think it's a unique situation but it's a situation that isn't acceptable anywhere."

The Prison Officers' Association said it had been making similar accusations since Scotland's only privately-run jail opened.

Good practice

Scottish assistant secretary Jim Dawson said: "Our main concerns would be for prisoners with mental health issues and suicidal tendencies.

"The investigation alleges that profit is being put before good practice and this is unacceptable.

"If the allegations are substantiated, we believe this is defrauding the Scottish public."

Scottish National Party MSP Alex Neil called for the immediate suspension of Premier's contract to run the jail.

An investigation is now under way into the allegations raised in the programme Premier Custodial Group

"The BBC documentary totally vindicates all the allegations I have been making for six years that the management of this prison is disastrous," he said.

"From the day this prison opened, the drive to make profit has been given over-riding priority."

A spokesman for Premier Custodial Group said three members of staff had been removed from training duties, although they were still working within the jail complex.

"An investigation is now under way into the allegations raised in the programme," he said.

The company pointed out that there had not been a suicide at the jail for two years, and stressed that the prison was safe and well run.