Health board bosses have so far failed in efforts to trace the family of a child who died at a flagship hospital, and they still do not know the youngster’s death could be linked to infected water on the site.

Nicola Sturgeon said it is her understanding that NHS Greater Glasgow and Clyde has not yet been able to get in touch with the relatives – although she stressed that is “not for the want of trying”.

In May, Scottish Labour leader Anas Sarwar revealed the child’s family “may not even know” their death could be connected to problems with the water at the Queen Elizabeth University Hospital campus in Glasgow.

The First Minister at that time gave him a “personal commitment” that every step possible would be taken to find them.

Mr Sarwar asked for an update at Holyrood on Thursday.

Ms Sturgeon said the board “have not located the family”.

She added: “As I absolutely understand it, that is not for the want of trying and effort and that appropriate steps will continue to be taken.”

Mr Sarwar demanded police investigate the death, in the same way that officers are now looking into the death of 10-year-old Milly Main.

Milly died in 2017 after contracting an infection found in the water while being treated at the Royal Hospital for Children – part of the same campus as the QEUH.

Mr Sarwar has campaigned with Milly’s mother, Kimberly Darroch.

Raising the issue at First Minister’s Questions, Mr Sarwar said: “There should have been criminal investigations launched into both deaths as soon as the circumstances became clear.

“We know that two children’s deaths were linked to hospital infections. There is now a criminal investigation into one of those deaths, Milly Main.

“But the health board only referred Milly’s case to the Crown when Milly’s family applied for a fatal accident inquiry.

“They didn’t take the opportunity then to refer the second child, and they didn’t take the opportunity when the case note (review) was published.”

The review established “two children’s deaths were linked to hospital infections”, and Mr Sarwar demanded to know why the Scottish Government – which had commissioned the review – had not then reported the second death for investigation.

Ms Sturgeon told him: “It is not up to me what cases are investigated from a criminal perspective and which are not.

“Rightly that is not up to me, that is up to the police and Crown Office.”

It was confirmed last month that the Crown Office, which has a duty to investigate all sudden, unexpected and unexplained deaths, had instructed Police Scotland to investigate four deaths at QEUH, including Milly’s.

A separate public inquiry is also looking into issues with the construction of the Glasgow hospital campus and the Royal Hospital for Children and Young People in Edinburgh.

The First Minister said the inquiry, together with the police investigation, means it “would not be right, appropriate or indeed helpful” for her to go into details.

But she insisted: “A government that has established a full, independent statutory public inquiry cannot be said to be a government that is somehow trying to hide away from getting to the truth. We want the answers.

“I want to leave no-one in any doubt about how seriously I take these issues, how seriously the Government takes theses, and how determined we are through the process we have established in the public inquiry to get to the answers, to get to the truth.”