The Scottish Hospitals Inquiry is to hold its final session just days after a health board admitted infections of some child cancer patients were probably linked to a hospital water system.

NHS Greater Glasgow and Clyde (NHSGGC) had previously denied bacteria in the water at the Queen Elizabeth University Hospital (QEUH) campus was to blame.

The investigation was prompted by concern about patient safety following a series of infections and several deaths including that of 10-year-old Milly Main.

The inquiry, which has been looking at the planning, design, construction and maintenance of hospitals, will hear four days of final oral submissions before publishing a report later this year.

The first day of the final session will start with counsel for the inquiry, followed on Tuesday afternoon by the Greater Glasgow health board.

The change of position by NHSGGC emerged at the weekend in a document submitted ahead of the final inquiry session.

Having reflected on the expert evidence, it said there was “on the balance of probabilities” a causal connection between a high rate of bloodstream infections among child patients and the hospital environment, particularly the water system.

It said infection rates fell after remedial work was carried out in 2018, including changes to the water system.

During earlier evidence sessions, senior officials had maintained the infections were complex with multiple possible sources.

Families of children who died following infections have welcomed the admission about the water system, but said it should have come far sooner.

Kimberly Darroch, mother of 10-year-old Milly Main, who suffered septic shock after an intravenous line became infected in 2017, said: “As a mother, I’ve spent six years fighting for answers that should have been given at the very beginning”.

Milly, who was being treated for leukaemia, was in remission at the time of her death.

John Cuddihy, whose daughter Molly died aged 23 last August, seven years after she was infected said it was “overdue recognition” of problems with the water system that families had been warning about for years.

The Glasgow hospital campus which includes the QEUH and the Royal Hospital for Children opened to patients in 2015, after being built at a cost of £840m.

But within a few years a number of patient deaths and infections led to concerns about the water and ventilation systems.

Former Health Secretary Jeane Freeman ordered public inquiry in 2019, with its remit also including problems at Edinburgh’s Royal Hospital for Children and Young People (RHCYP)

The opening of the Edinburgh site had been delayed at the last minute after safety concerns about its ventilation system.

The public inquiry’s interim report on the RHCYP has already been issued, saying a spreadsheet error by the health board led to the system being wrongly specified.