Costs for private referrals soared by almost 2000% after a Glasgow brain injury unit was hit by a major sewage leak.

Figures show cash-strapped NHS Greater Glasgow and Clyde paid out more than £200,000 in three months for surgery which could not be carried out at the Institute of Neurosciences.

Elective operations were cancelled after raw sewage leaked into recovery rooms from pipes in the wards above in February and surgeons refused to operate.

Read more: Patients anger over surgery delays at sewage hit brain injury unit

The head of NHSGGC, Robert Calderwood, said 18 leaks or floods in as many months had led to a backlog of operations at the ageing unit, which is based at the Queen Elizabeth University Hospital, but is not part of the new build.

Health workers union Unison blamed cutbacks in maintenance and building repairs for the problem.

Figures show the health board paid £10,897 to the private sector for three operations from January to March but was forced to farm out 52 ops to the private sector from April to June at a cost of £205,910.

The figures, obtained by Freedom of Information laws, also show that the health board paid £562,951 to the private sector for all surgery from April to June, compared to £199,379 for the first three months of the year.

Some operations were carried out in other NHS units including the Queen Elizabeth University Hospital before the theatres re-opened on May 17.

Unison’s Regional Organiser, Matt McLaughlin said: “This is of course a concern and has been created by design and building failures in existing building stock.

“Unison will be monitoring this closely to ensure that cut backs in maintenance and building repairs don’t lead to more money being wasted in the private sector.”

A spokesman for NHSGGC said: “NHS Greater Glasgow and Clyde strives to provide prompt access to high quality care and treatment for all our patients.

Read more: Patients anger over surgery delays at sewage hit brain injury unit

“To ensure our patients are seen within the waiting times guarantee, we have on occasions been required to carry out additional work.

“The majority this additional work has been carried out within our own hospitals at weekends and in the evenings.

“A small element of this additional work has involved the use of the private sector and this work has been awarded in line with national tendering processes.”

The board has been awarded a £7million contract to build a new state-of-the-art theatre suite at the Institute of Neurosciences, which is due for completion in early 2017.