The Scottish breast screening programme is to be reviewed after it emerged invitations to thousands of women were delayed.

The Scottish Government has asked Healthcare Improvement Scotland (HIS) to examine the programme run by NHS National Services Scotland (NSS).

An investigation by NSS identified that about 3,800 women across Scotland had not received timeous breast screening invitations.

The problem first came to light when a woman contacted a breast screening centre in August 2015 to report that she had not been called for an appointment for more than three years.

Women aged between 50 and 70 are invited for routine screening once every three years while those over 70 can refer themselves once every three years.

The Scottish Government said the problem was a "historical issue" with the invitation process and all of the affected women had since been identified and offered fast-tracked appointments.

Chief medical officer Catherine Calderwood said: "In light of the issues that have been identified, we have asked Healthcare Improvement Scotland to undertake a review of this particular incident to see why some women were not invited. This will ensure that women across the country continue to be offered the best possible service.

"Scotland was one of the first countries in the world to establish a national breast screening programme and it is vital than we ensure that it continues to provide a high-quality service which meets the needs of women.

"I would encourage all those invited for breast screening to take up their offer."