An emergency call was delayed by almost an hour because of a technical problem that disrupted 999 phonecalls to the Scottish Ambulance Service, health secretary Nicola Sturgeon has revealed.

Ms Sturgeon apologised to all those affected by “distressing” delays after telephone problems struck at the service`s three dispatch centres in Inverness, Glasgow and South Queensferry.

She said lessons must be learned from the incident on July 21 as she told how 125 patient calls had to be diverted to Northern Ireland and England using the ambulance service`s “buddy system”.

A total of 44 of these were category A calls - which deal with potentially life-threatening cases.

In one of these cases, Ms Sturgeon said there was a delay of 57 minutes in the information being passed to the Scottish Ambulance Service.

However, she said that in more than half of the category A calls the delay in getting information to ambulance service staff in Scotland was less than 10 minutes, with an average delay for category A calls of 13 minutes.

Ms Sturgeon made a statement to Holyrood on the technical problems that hit the Scottish Ambulance Service that day.

She said: “I am very aware that these delays will have been distressing to the individuals concerned. I would like to convey my apologies, and those of the ambulance service chair, to all of them.”

The health secretary also stressed there had been “no adverse outcomes attributable to the delays associated with the buddy system”.

She added that the Scottish Ambulance Service was conducting a “thorough and detailed” review of what had happened.

That will then be provided to the health secretary by the end of November.

Ms Sturgeon stressed: “The difficulties experienced by the service are being responded to with the thoroughness that they deserve.”