The head of the prosecution watchdog said the backlog of almost 30,000 cases is continuing to grow during the pandemic.

The body has called for action to address delays, especially in sexual crime cases, in which Crown Office staff are resetting key dates to “mask the true journey time of cases”.

Laura Paton, chief inspector of prosecution, said that the Crown Office needs extra funding to cope with the mounting backlog.

The Scottish Courts and Tribunals Service (SCTS) said the average waiting period for trials has doubled to 12 months in the High Court, 15 months in Sheriff solemn cases and six months in summary cases.

Ms Paton commented: “Modelling has shown that it may be several years before the backlogs are addressed. This will have significant consequences for victims, witnesses and the accused in cases awaiting trial and risks damaging public confidence in the criminal justice system.

“It will also have significant consequences for the work of COPFS for some time to come.

“A key issue will be the ability and capacity of the service to maintain a high standard of communication and engagement with victims and witnesses in newly-reported cases as well as those who have been awaiting the conclusion of their cases for a prolonged period of time.”

Ms Paton also warned that there will be “further significant demand” Crown Office resources over its role in the investigation of deaths following the pandemic.

The Lord Advocate directed in May that people who had died and may have caught the virus in the course of their employment and those who contracted the virus in care homes should be reported to the Crown.

Ms Paton said: “COPFS is one component in a wider criminal justice system and it is essential that the system in its entirety works effectively – this includes policing, prosecution, defence, courts, prisons, criminal justice social work and the voluntary sector.

“Improvements and investment in one area will not produce the desired outcome if not matched system-wide.”

A Scottish government spokesman said: “We understand the impact trial delays have on victims, witnesses and accused, and have provided £12 million to the SCTS for remote High Court and sheriff jury centres to restore pre-Covid court capacity, on top of £3m to develop court technology.

“With the introduction of remote jury centres, High Court evidence-led trials are 17 per cent higher than the average monthly pre-Covid level and the latest figures show that evidence led summary trials are now 85 per cent of the average monthly pre-Covid levels.

“Many administrations are experiencing the impact of Covid-19 on court volumes. Figures from England and Wales show outstanding workloads in the Crown Court rose from over 39,300 cases pre-Covid to just over 53,000 by November.”