Taxpayers are forking out hundreds of thousands of dollars a month in double-time wages for prison officers to guard inmates at hospitals because Serco is only contracted to supervise six visits a day Statewide.
The revelation comes as internal documents obtained by The West Australian reveal how thousands of dollars are spent on moving individual prisoners around WA, often by chartering a whole aircraft.
A row has broken out over prison transport costs in the fallout of the escape of two prisoners from a prison van at Geraldton airport a week ago amid allegations of high quotes and spending.
WA's prisons boss James McMahon said yesterday that the reasons for the escape were "procedural and mechanical" but refused to give more details.
"Hospital sits" used to be the responsibility of the Department of Corrective Services but are now carried out by Serco Australia, which is contracted to perform one regional and five metropolitan supervisions a day.
Official figures show the DCS is increasingly picking up hospital sits requested of Serco because the contractor does not have the staff.
The department, reluctant to deplete the number of guards at prisons, usually asks off-duty prison officers to supervise medical visits at double their normal hourly rate.
In 2011-12, DCS carried out 122 hospital sits and 1634 were done by Serco. Last financial year, the DCS did 133 hospital sits and Serco 1908.
The DCS was unable to say how much overtime it paid its staff to do the sits.
Records obtained by _The West Australian _ show DSC officers from Hakea were paid about $190,000 overtime to supervise 36 prisoners in hospital in the four months to September.
Officers were paid between $65 and $70 an hour and the highest single overtime pay packet was $1167 paid to one officer who spent 17 hours watching a prisoner in hospital on June 21.
"With an increasing and ageing prisoner population and the department's commitment to providing access to medical treatment and care, the requirement for hospital sits will continue to increase," a DCS spokesman said.
He said variations in demand could be accommodated within the 10-year contract struck in 2011. WA Prison Officers Union secretary John Welch disputed this, saying the figures backed up anecdotal reports from his members that the responsibility was increasingly falling on them.
"The public sector, at overtime rates, is providing work that should be provided by the contractor and if it's not work that should be provided by the contractor, then the contract must be deficient," he said.
Shadow corrective services minister Paul Papalia said the justification for privatisation was usually to provide a cheaper or superior service than what the public sector could provide.
"Well in this case, it's not meeting the requirements and it's more expensive," he said.