A further ten cases of infections linked to the Queen Elizabeth University Hospital water contamination crisis were identified as far back as 2016, according to reports.
Anas Sarwar MSP said a NHS whistleblower has claimed a clinician-led probe uncovered the incidents.
They are on top of the 26 incidents revealed in 2017 by the same review, including the death of Milly Main, and on top of 23 cases in 2018 reported by Health Protection Scotland – all in paediatric cancer.
The news comes amid a Sunday Post story that the Health and Safety Executive listed problems with the way staff were trained and equipped to deal with highly contagious diseases, in November 2018.
A report in the Scottish Mail on Sunday also tells how an investigation has been launched after a third child was left fighting for their life after an infection linked to the water contamination crisis.
The latest case, which was said to have happened in September, comes after the deaths of two children in 2017.
All three were patients in a ward that was later found to have been affected by water contamination.
Health secretary Jeane Freeman said she has not been shown the Health and Safety Executive report into the hospital when it came out in November last year.
On Sunday, Ms Freeman explained ministers “wouldn’t normally see” HSE reports, and added that it was about a separate part of the hospital, although she went on to say senior Scottish Government officials were now looking “very carefully” at what information comes to ministers.
She also said she could not give definite numbers on how many infection cases there had been as work is “still going on”.
She added: “And that is partly why I escalated that board to level four, so we can get that data and look across all the inspection reports, to be sure exactly how many children were affected.”
The Scottish Government announced on Friday the escalation of NHS Greater Glasgow and Clyde (NHSGGC) to stage four of the NHS Board Performance Framework.
In Scotland, a five-stage scale is used to show the level of oversight for stricken health boards.
Mr Sarwar said: “These latest revelations from an NHS whistleblower show that problems at this hospital have been going on for years.
“It’s clear that action should have been taken much earlier by senior managers to prevent the tragedy which unfolded.
“Doctors responded to concerns about the circumstances of Milly’s death by starting the formal whistleblowing process in September 2017.
“Dedicated staff repeatedly raised issues about the water supply with senior management, but they weren’t listened to.”
A NHSGGC spokeswoman said the hospital already had suitable respiratory protective equipment, protective gloves and health surveillance for staff in place, but the Health and Safety Executive identified that they needed to be enhanced.
She added that the board prepared and implemented an action plan which was submitted to the Health and Safety Executive in late December 2018.
Regarding the third child reported to be in a critical condition, she said they have offered to meet the family and made arrangements for them to meet experts to discuss their child’s care.
Jane Grant, chief executive, said: “We completely understand this has been a distressing time for families and staff.
“Unfortunately there will always be a small number of patients who develop infections because of the seriousness of their illness and we are fully committed to supporting them and their families at this difficult time.
“There are clearly lessons for us to learn in how we communicate with families during these periods.
“We welcome the opportunity to work with parents and professor Craig White, who has been appointed by the cabinet secretary for health, to consider how we can improve our information flow.”
An investigation has found no links between the individual infections and no link between the infections and the ward environment, the spokeswoman added.
Health Protection Scotland (HPS) has also concluded there is no evidence to support the continued restriction of new admissions to Ward 6A at the Queen Elizabeth University Hospital.
In addition, HPS has been commissioned by the chief nursing officer, Scottish Government, to undertake a review of NHSGGC haemato-oncology data, which includes data from 2016, and this will be published on Tuesday.