The police call centre which took the message about the couple who had crashed off the M9 had a 10% absence rate around a month before the incident, it has emerged.
The Scottish Conservatives, which uncovered the figures, described the situation at Police Scotland’s east service centre in June as “completely unacceptable”.
Data also shows that service centre staff around Scotland have worked thousands of hours of overtime since the start of the new financial year.
Lamara Bell, 25, and her boyfriend John Yuill, 28, were involved in a crash off the M9 near Stirling on Sunday July 5 after visiting the Loch Earn area.
The incident was reported that day via a 101 call to police from a member of the public, but the message was not logged in the system and no action was taken at the time.
The pair were only discovered in the car three days later, on Wednesday July 8, after police received a further call to the scene.
Mr Yuill was found dead inside the blue Renault Clio. Ms Bell, who was discovered alive but critically ill, died in hospital in Glasgow a week on from the crash.
An independent investigation is under way and a review of all police call handling is being carried out by Her Majesty’s Inspectorate of Constabulary in Scotland (HMICS). Police Scotland Chief Constable Sir Stephen House has faced calls to resign.
Figures contained in a Scottish Police Authority report from last month show that in the force’s police service centres – which handle non-emergency 101 calls – there were 36 members of staff absent as of mid-June.
That included 15 absent from the east centre at Bilston Glen, which is understood to have taken the call about the crash. The 15 absences, recorded on June 11, equated to an absence rate of 10.6%.
Figures in the report also show that staff in Scottish call centres had worked more than 8,300 hours in overtime from the start of April to “mitigate” the impact of staff vacancies.
Scottish Conservative justice spokeswoman Margaret Mitchell said: “This is a deeply distressing tragedy, all the more so because the warning signs that emerged months ago were completely ignored by the Scottish Government.
“A 10% absence rate is completely unacceptable in a high pressure environment where people’s lives depend on calls being handled quickly and efficiently.
“Service centre staff are already overburdened from excessive centralisation, but the sheer number of vacancies and lost advisor hours are only putting them under more strain.
“The buck stops with the Scottish Government on this and the public will no doubt wonder why it is constantly on the back foot with Police Scotland.”
Scottish Liberal Democrat leader Willie Rennie also voiced concerns.
He said: “This is further evidence of the difficulties that staff operating within police control rooms are facing.
“We know that these are high-pressure, high-stress jobs. The fact that 10% of staff were absent at Bilston Glen when this report was published last month demonstrates clearly the workload pressures that the remaining staff at these crucial facilities are facing.
“This underlines the need for a wider review into the operations of Police Scotland following the tragic events in Stirling.”
A Scottish Government spokeswoman said: “An action plan was put in place in April by Police Scotland and the Scottish Police Authority (SPA) to address recruitment and absence rates and as a result rates are improving.
“Action continues to be taken and the Scottish Government receives regular monitoring and assurance reports from the SPA.”