The Bilston Glen service centre in Midlothian took the call from a member of the public reporting a car off the road near Stirling – a report which police then failed to follow up.
Lamara Bell, 25, and John Yuill, 28, lay undiscovered in their wrecked car beside the M9 for three days – with both dying as a result of their injuries.
A police probe into call handling on the back of the incident is set to be published this week, but whistle-blowing staff are also understood to have put together a list of bungled calls which could have led to more tragedies.
It is believed the secret dossier may have heaped pressure on Sir Stephen House, Police Scotland’s chief constable, ahead of his dramatic resignation last week.
Lib Dem leader Willie Rennie said: “From what I understand there is a dossier of near misses that has been prepared by staff at Bilston Glen.
“I think it was inevitable Sir Stephen was going to go. The mounting evidence against him made it pretty clear. But, reading between the lines, it’s pretty clear he was pushed.”
The news comes as the brother of Lamara Bell called on police to report failings in the force in a bid to “save any more people from dying”.
Martin Bell yesterday urged officers to “come forward and say it as it is”, adding: “If 999 calls are being unattended it is serious and it’s only a matter of time before there is another fatality due to this mess the system is in. It’s time to stand up and make the change.”
The police report into the performance of call centres is expected to severely criticise the force and make at least one recommendation as to a way forward.
Labour justice spokesman Graeme Pearson said it was time for police bosses to start listening to their rank-and-file staff. He said: “The chief constable, Scottish Police Authority and the justice secretary let them down by repeatedly being deaf to the warnings they made over the past three years.”
Chief Superintendent Alan Speirs said: “Calls received by Police Scotland contact and service centres are reviewed and assessed on a daily basis.
“Such review work is carried out to ensure incidents are prioritised correctly, and to ensure the public receives an effective and efficient service.”