Lamara bell, 25, lay severely injured but conscious at the bottom of an embankment off the M9 near Stirling for days – even though calls had been made to the police in the hours after the crash.

Her partner, John Yuill, 28, who had been driving, died soon after the crash in July 2015.

The FAI found Ms Bell would likely have survived but for “organisational failure” in Police Scotland’s call-handling system – which allowed a human error to go undetected.

Sheriff James Williamson said Ms Bell’s injuries, along with the delay in rescuing and treating her, led to her death fours days after she was found.

Sheriff Williamson said that the man who failed to log the call had been inadequately trained and was left largely unsupervised.

The deaths had had a corrosive effect on the public’s confidence in Police Scotland.

Yet his report made no recommendations for any future actions. He said Police Scotland had learned the lessons of its procedural failures in the past nine years.

Andy Shanks, who leads on death investigations for the Crown Office, said: “We recognise that the time taken for our investigation and criminal proceedings to conclude and to initiate the inquiry must have been enormously difficult for the families of Lamara Bell and John Yuill.”

He added: “The procurator fiscal service will continue to keep in contact with the families following the conclusion of this complex and lengthy FAI and answer any questions they may have about the determination.”

Willie Rennie MSP, who had warned of incompetence at Police Scotland in the run-up to the failure to respond, said: “In the months before the tragic deaths of Lamara Bell and John Yuill I repeatedly warned Nicola Sturgeon about the problems at the call centres but the SNP government did nothing to stop the cavalier closures.

“It was SNP ministers who drove through the rushed centralisation of the police and ignored the concerns of those on the ground. Today, SNP ministers need to take responsibility for their part in this and admit their terrible political decisions had tragic consequences.

“The agonising nine year wait to find out precisely what happened is unforgivable. The broken FAI system is adding to the families’ torment. I’m sick of seeing families become trapped in this prolonged process and the government needs to make it stop by accepting the need to completely overhaul FAIs.”