More than half of the special performance reports compiled by Scotland’s national exam body over a five-year period to help improve pupils’ exam grades were bought by private schools, an investigative news platform has revealed.

Performance reports - which can cost up to £929 - are compiled by the Scottish Qualifications Authority (SQA) and are intended to “help centres ensure that they are preparing candidates for course assessment in the most appropriate way”.

Critics, however, have pointed out that independent schools are better able to afford the detailed investigations after figures published on investigative news website The Ferret revealed that, over a five-year period, 56 per cent of these reports were bought by private schools.

Related: SQA exam body selling its services ‘all over planet’

Background: Headteachers spend £132m trying to close attainment gap

Short read: The attainment gap for looked-after children

Pisa: No sign of attainment gap cash ‘making an impact’

Data released under freedom of information legislation shows that 30 performance reports were issued to 21 schools and colleges by the SQA between 2013-14 and 2017-18. A total of 17 of the reports - or 56 per cent - were bought by private schools.

State schools, meanwhile, purchased eight reports (27 per cent) and five were purchased by further education colleges (17 per cent).

Of the nine reports produced in 2018, just one was for a state school, two were for colleges and the remaining six were for private schools.

The SQA - a Scottish government quango - stressed that the service was “a very small part” of the help it offered.

Exam ‘advantage’ for private schools

However, Gary Walsh, an education writer and researcher at the University of Glasgow, told The Ferret that the figures suggested that direct support from the SQA could “effectively be bought for certain pupils” and the service was “creating a disproportionate advantage for pupils in private schools who are better placed than state schools to be able to pay for it”.

Walsh added: “This is clearly an example of inequity being hardwired into the system.”

Scottish Labour education spokesperson Iain Gray said the revelations were “yet another example of pupils with the greatest educational advantages anyway using financial clout to gain even more advantage”.

The SQA insisted that it did not profit from the service, and that charges were simply to “recover the cost of the senior SQA examiner’s time”.

It added that performance reports were available to all SQA centres and that the volume of reports in relation to the number of centres was very low.

The SQA added there were “significant online resources to assist teachers in gaining a comprehensive understanding of marking guidelines”.

A spokesperson said: “We would always encourage SQA centres to take advantage of the wide range of free-to-use resources produced by our understanding standards programme, which include free-to-attend events, webinars and audio resources that are designed to support centres and practitioners with their understanding of national assessment standards.”