New figures show a fatal accident inquiry (FAI) has taken more than nine years to complete.
Data released by the Crown Office and Procurator Fiscal Service showed that, as of October 28 last year, one FAI, stretching back to 2012-13, had not been concluded after 3427 days.
Another FAI into the death of a person in custody remained outstanding 2678 days – more than seven years – after being called in 2014-15.
In total, some 164 inquiries remain outstanding, including 53 where the deaths occurred in 2020-21.
Copfs released data on investigations into sudden deaths or accidents following a freedom of information request from the Scottish Liberal Democrats.
Scottish Lib Dem justice spokesman Liam McArthur called for a legal duty to be put in place for inquiries to begin within one year of the death.
“The fatal accident inquiry system should be about offering closure for families and learning lessons for the future,” he said.
“A system that takes almost ten years to come to its conclusions is next to useless and an insult to families.
“Across Scotland families are desperate for answers about the fates of their loved ones but after a decade evidence is lost and memories fade.
“The Scottish Government have had plenty of opportunities to reform fatal accident inquiries but they have clung to a failed system.
“It is time FAIs were removed from the remit of the Crown Office and handed to a new body charged with ensuring that inquiries begin within a year and results are presented in a timely fashion.”
A Copfs spokesman said: “Copfs has increased the resources available to its death investigations teams and changed working practices with a focus on progressing older cases.
“These measures are delivering a significant improvement in the service delivered by the Procurator Fiscal in this important area of work.”
A spokesman for the Scottish Government stressed that FAIs fall under the remit of the Lord Advocate, saying: “The Crown Office has significantly reformed the arrangements for the investigation of deaths.
“These reforms have already resulted in reductions in the duration of death investigations and it is expected that they will continue to do so.
“Parliament considered and modernised the law on FAIs in 2016 and there are no current plans to revisit the legislation.”