An E Coli outbreak that led to the death of a child was caused by Dunsyre Blue cheese, a health watchdog has found.

Health Protection Scotland released its report into the spread of the bacteria on Wednesday.

It concluded the unpasteurised cows' milk cheese made in Lanarkshire was the source.

Lanark-based producer Errington Cheese has contested the findings, which had led to the product being banned by Food Standards Scotland.

The E Coli outbreak occurred in two phases in July and September last year, investigators said, with a total of 26 people infected.

Of those who tested positive for E Coli 0157, 17 had eaten the blue cheese prior to developing symptoms, with many consuming it as part of a cheese board course at hotels or restaurants.

During the second cluster of cases in September last year, a three-year-old girl from East Dunbartonshire died from complications of the infection.

The watchdog found Errington Cheese did not monitor the presence of the shiga toxin, which is linked to E Coli, during the production of its artisan cheese.

The report stated: "Extensive investigations concluded that the source of the outbreak was the consumption of an unpasteurised cheese - Dunsyre Blue.

"This conclusion was based on evidence from epidemiological and food chain investigations and supported by microbiological evidence and deficiencies identified at Errington Cheese Limited in the procedures in place for the monitoring and control of STEC (Shiga toxin producing E Coli)."

Health Protection Scotland's incident management team added: ""Potentially pathogenic E Coli were able to enter and survive the cheese production process at the food business.

"Positive results were obtained for cheese produced over a period of four months, indicating a systematic potential for STEC to enter the process and contaminate final products."

The watchdog's investigation found another Errington Cheese, Corra Linn, contained a potentially infectious form of E Coli, which led to it being seized by council officers.

In response to the action by Food Standards Scotland and South Lanarkshire Council, Errington Cheese went to court and had the ban on its Lanark Blue and Corra Linn cheeses lifted after a judge ruled it "unlawful".

In response to the report, Errington Cheese said: "We received a copy of the outbreak report late yesterday afternoon.

"On an initial reading, all of our concerns regarding the investigation into our cheese and the outbreak of illness remain.

"We believe that more detailed investigations into the cause of the outbreak are needed. This is particularly in relation to those cases where Health Protection Scotland were unable to find any direct link to Dunsyre Blue.

"Health Protection Scotland have now had their chance to present their opinion on what they believe happened.

"That being so, we sincerely hope that they will desist from attempting to frustrate our attempts to uncover the facts, particularly in relation to those cases which don't fit with their hypothesis.

"We call on them once again, as we did in August 2016, to let us have access to the evidence relating to their investigations."

Geoff Ogle, Food Standards Scotland chief executive, welcomed the Health Protection Scotland report.

He said: "Food Standards Scotland is satisfied that the evidence and conclusions presented in this report fully support and justify the decisions that we took to protect consumers.

"All of our decisions and actions were taken with the sole aim of protecting public health.

"This report should allay any concerns with regards to our decisions and assure others that our actions were evidence based. That will always be the case."