The operator of Kilmarnock Prison has defended its record following a BBC investigation which alleged problems with the running of the jail.
The chief of Kilmarnock Prison defended its record
Phil Edwards, of Premier Custodial Group, accepted there had been individual failures at the prison.
Speaking on Newsnight Scotland he defended staffing levels and training for new officers as "adequate".
An undercover reporter for Real Story filmed officers turning a blind eye to the use of drugs and alcohol.
Mr Edwards told Newsnight Scotland that some of the material in the documentary was "disturbing".
However, he promised that an investigation already under way would be thorough and revealed that a similar inquiry has been ordered at the three English prisons run by the group.
Mr Edwards said conditions had improved in recent years and pointed out that there has been no suicide at Kilmarnock for almost two years.
He denied that the problems of staff cutting corners was to do with staffing levels, which he said were adequate for the prison.
Premier Custodial Group said three members of staff had been removed from training duties, although they were still working within the jail complex.
Scottish Prison Service spokesman Tom Fox voiced "real concerns" about the allegations, while the Prison Officers' Association said it had been making similar accusations since Scotland's only privately-run jail opened.