Daren Fitzhenry said he found “a number of areas where performance and practice fell short” despite recommendations he made in 2018.

His report comes a week after the government found a ‘lost’ email in its records central to the £250 million Calmac ferries fiasco.

It covers two years from April 2019 to the end of March 2021 and draws upon internal Scottish government FOI data as well as a review of 76 FOI cases.

Mr Fitzhenry found “substantial problems in the Scottish government’s ability to track, monitor and report on (and therefore improve) FOI performance”, and “evidence of significant delays and organisational ‘bottlenecks’ in some areas”.

He said: “It’s reassuring to see that the Scottish government has made significant improvements in a number of key areas.

“However, it is also clear that work remains to be done. While the pandemic was undoubtedly a factor in some of the issues we identified, it was evident that problems with records management; compliance with procedures; and the recording, tracking and monitoring of FOI requests stem from wider, more systemic, concerns.

“FOI is an important right. It enables people to understand more about the public services they use and the decisions which affect them; and supports public engagement.”

Conservative MSP Craig Hoy said: “Persistent problems with record-keeping have made it difficult for the Information Commissioner to fully investigate the government, and though there seems to have been some recent progress on improving FOI practices, too many responses are held up by the involvement of government ministers and special advisers.”

Labour MSP Neil Bibby said: “There is a rotten culture of secrecy at the heart of the SNP that threatens the fundamental principles of transparency and openness in government.”

Parliamentary business minister George Adam said: “We have worked hard to restore turnaround times. Over the past two years response rates for requests issued within 20 working days have improved to around the average for Scottish public bodies, at 86 per cent. We have, at the same time, responded to a steep increase in the volume of FOI requests - handling a record 4,200 requests last year - 25 per cent more in 2021 than the previous year, the vast majority on time.”