Scotland's police chief today apologised to the angry families of a couple who were left in a car wreck for three days after the accident was reported, acknowledging that the force had "failed both families".
John Yuill died and Lamara Bell was critically injured in the crash on the M9 on July 5, but the pair were only discovered by officers on July 8.
Police chief constable Sir Stephen House said information from a call received on Sunday had not been entered into police systems.
There have been calls for an independent investigation of the case.
The Police Investigations and Review Commissioner (PIRC) is reviewing the handling of the incident.
Yuill, 28, was killed and Bell, 25, is in a medically induced coma at Queen Elizabeth University Hospital in Glasgow, having suffered kidney damage from dehydration from lying in the wreckage for so long. Her condition was described by doctors as "very serious", the BBC reported.
Her family said they were angry and disgusted by the way Police Scotland had handled the case.
House said a member of the public had called the 101 non-emergency number at about 11:30 am on Sunday after seeing the car down the embankment near the Bannockburn slip road.
The call had been taken by "experienced officer". However, "for reasons yet to be established" this had not been entered into systems or sent out to operational teams in the area.
House said: "Firstly I want to apologise to the families of John Yuill and Lamara Bell and to the people of Scotland for this individual failure in our service. Everyone in Police Scotland feels this most profoundly.
"I completely understand the level of concern being raised about the circumstances surrounding the handling of the incident and, in particular, Police Scotland's response to information received.
"That we failed both families involved is without doubt."
House said the incident had been "rightly" reported to PIRC, and that police would remain independent of the investigation.
