Legal proceedings against Police Scotland are anticipated following the deaths of a couple whose car left the M9 near Stirling in 2015.
John Yuill, 28, died at the scene of the crash and his partner Lamara Bell, 25, died later in hospital.
It took police three days to respond to the incident, despite a call being made to them.
Lord Advocate James Wolffe QC is understood to have notified Chief Constable Iain Livingstone of the move.
Mr Livingstone was not in charge of Police Scotland at the time.
The move was first reported in the Daily Record newspaper.
Mr Livingstone said: “Lamara Bell and John Yuill’s deaths were a tragedy and my thoughts and condolences are with their families and loved ones.
“Police Scotland has fully assisted the Crown Office throughout their inquiries and will continue to engage in due process.”
A spokesperson for the Crown Office and Procurator Fiscal Service said: “The case team and staff from our Victim Information and Advice service have communicated with family members and their legal representatives throughout, and will continue to keep them informed of any significant developments in relation to the investigation.
“In order to protect any potential proceedings the Crown will not comment further at this stage.”
In a statement released by solicitors Digby Brown, Ms Bell’s family said: “We will not comment on any new or ongoing proceedings until they have all concluded.”