Around 800 Scottish public sector workers whose original jobs have been abolished remain on the payroll at an estimated cost of at least £27 million a year.
The employees work across the NHS, councils, the Scottish Government and public bodies and have been placed in redeployment arrangements while they wait for permanent alternative roles.
Figures obtained through Freedom of Information requests by The Sunday Times found 255 workers had been without a fixed post for more than a year.
At least 49 had remained on full salaries for five years or longer after the jobs they were originally employed to do ceased to exist.
A NHS Highland employee has been without a defined permanent role for 17 years. NHS Highland has 88 employees in redeployment, according to the investigation, including 26 who have been without permanent posts for at least five years.
The health board said it follows the national NHS Scotland Redeployment Policy and that staff affected by organisational change can continue making a contribution while alternative employment is sought.
The national policy is designed to find suitable alternative employment for workers whose posts are no longer required or who cannot continue in their existing roles.
It gives employees awaiting redeployment priority for suitable vacancies before posts are opened to wider recruitment.
Across NHS Scotland, around £16.8 million a year is being spent on 315 employees without permanent posts.
A further 185 NHS workers were identified through the investigation but complete salary information was not provided, meaning the overall cost could be higher.
Scottish councils were estimated to be spending another £5.8 million a year on workers awaiting redeployment.
The findings have intensified scrutiny of the Scottish Government’s longstanding commitment to avoiding compulsory redundancies in the public sector.
The policy means organisations undergoing restructuring are expected to consider options including redeployment, retraining, natural staff turnover and voluntary severance before making workers redundant.
The Scottish Government reaffirmed the commitment this month as it set out plans for substantial restructuring of NHS Scotland.
Its health reform programme states that workforce changes will be managed through measures including redeployment, retraining, reskilling, vacancy management and voluntary exits.
The figures have prompted calls for Scotland’s public spending watchdog to investigate.
Scottish Conservative finance and local government spokesman Craig Hoy said: “Scotland’s public sector has become a gravy train for insiders with a ghost workforce of hundreds costing taxpayers millions every month.
“Some have been left languishing in zombie jobs for 17 years, a jaw-dropping indictment of a system completely out of control.
“The Auditor General must investigate this scandal and establish how taxpayers’ money is being squandered on a system that has been allowed to spiral out of control.”
The issue comes as ministers attempt to reduce the size and cost of Scotland’s public sector.
The Scottish Government has previously set an ambition to reduce the devolved public sector workforce by an average of 0.5 per cent a year through to 2029-30.
The Scottish Fiscal Commission said last month that ministers had yet to provide sufficient evidence of progress towards planned workforce and efficiency savings.
Official figures show 553,600 people were employed in Scotland’s devolved public sector in June, an increase of 6,060 compared with the previous year.
A Scottish Government spokesperson said its no compulsory redundancies policy remained in place.
They added: “Public bodies are expected to ensure that they deliver value for money and to see that all staff, including those who are redeployed, are engaged in appropriate work for their pay scale.
“For example, the NHS has clear redeployment policies that helps boards to make use of staff with experience and expertise even while their posts may change.
“Public bodies manage their workforce through steps such as redeployment, attrition, vacancy management, reskilling and, where necessary, voluntary severance.
“These tools will form part of our work to deliver public service reform – focusing on frontline delivery, with the right staff in the right roles to deliver real improvements in public services.”