Covid care home deaths branded a "national disgrace" are under scrutiny by a specialist prosecution team.
It comes after lawlords in England ruled this week that the UK Government acted unlawfully in ordering the discharge of untested patients from hospitals into care homes during the pandemic.
Renfrewshire was particularly hard hit by the "shameful and unforgivable" care home deaths, which saw scores of residents hit by the virus.
Crown Office figures revealed in April 2021 showed Erskine Hospital was one of the worst hit in Scotland.
We also told last year how data from Public Health Scotland revealed dozens of untested hospital patients were sent back into Renfrewshire's care homes before a wave of covid deaths took hold.
It was revealed that in one case, a sick resident who had tested positive for Coronavirus was sent to Paisley's Elderslie Care Home without a negative follow-up test.
In the first three months of the pandemic, 27 residents died at the Advinia Health Care-operated home in Fulbar Road,
Now, the Crown Office's specialist Covid Death Investigation Team will look at more than 4,000 deaths in care home facilities, it has been announced.
The Crown Office and Procurator Fiscal Service (COPFS) run probe is now looking at 5,191 deaths, including 4,042 care home residents.
A further 1,096 hospital deaths are now being examined, along with 38 deaths of workers and 15 deaths in custody.
Data also reveals that 573 care homes are now being investigated over one or more deaths.
The Erskine Hospital Care Home in Bishopton has the highest number under investigation with 36, followed by Rutherglen Care Home (29), Darnley Court Care Home in Glasgow (28).
Elderslie Care Home in Paisley is also being probed over 27 deaths.
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Files also show that Paisley's Royal Alexandra is being probed over 85 deaths, with only the Queen Elizabeth University Hospital seeing a higher number of deaths under investigation - with some 128.
The vast majority of care homes and most smaller hospitals have five or fewer deaths under investigation.
Paisley-based MSP Neil Bibby, who earlier called for a public inquiry into the deaths, blasted the "tragic consequences" sparked by the policy, saying: "Every death from this appalling virus was a tragedy and I know our community’s thoughts will be with the families of those who have died.
"From day one, the SNP Government were slow on PPE, slow to listen to the warnings from staff, slow on testing and slow to admit that untested and covid positive patients been discharged into care homes."
The West Scotland Labour politician added: "The treatment of care home residents and residential care staff throughout the crisis has been nothing short of a Scottish national disgrace. It is shameful and unforgivable.
"Sending untested and COVID positive patients from hospitals into care homes has now been deemed unlawful by a High Court judge in England. It is unthinkable that the public inquiry in Scotland would not reach the same conclusion here.
"The tragic consequences of government decisions on care homes have been felt across Renfrewshire and the whole country. This cannot be allowed to happen again".
The English ruling on government policy during the pandemic came after members of the public raised an action against Public Health England and disgraced former Health Secretary Matt Hancock.
Dr Cathy Gardner - whose father was a care home resident - and Fay Harris took the government to court alleging there had been failures in protecting residents.
They partially succeeded in claims against Public Health England and the secretary of state for health and social care.
The court found the policy did not take into account the risk to vulnerable residents from asymptomatic covid transmission,
An identical policy was followed in Scotland and bereaved families have said they are now weighing up legal action.
The Scottish Government has already appointed Lady Poole to head a public inquiry into Scotland’s handling of the pandemic.
The Crown Office team of 18 staff, which includes nine lawyers, works closely with the police and the Health and Safety Executive.
However, care home bosses have criticised Operation Koper as being “wholly disproportionate” and claimed it is “causing irreparable damage to the professional integrity of nurses and carers who are exhausted beyond measure in fighting the virus”.
