The climbdown comes after a Lib Dem Freedom of Information request last year revealed that 852,507,524 number plate records captured by automatic number plate recognition (ANPR) cameras across the country were held in a Police Scotland database, with data available from as far back as 2009.
Data retention laws require that any such information is only kept for crimes, while all other data must be deleted.
The Lib Dems had expressed concern that the retention of so much information relating to innocent individuals was infringing on people’s civil liberties.
The number of records deleted was revealed by the police in response to another Freedom of Information request submitted by the Lib Dems.
Information provided by the police showed 547,459,904 number plate records had been disposed of.
Police Scotland’s response revealed that in June last year a senior officer had instructed that number plate data should be “weeded out” two years after it was added, apart from those required for ongoing investigations.
It said this deletion was in line with Home Office and Information Commissioner’s Office guidance. It added that “manual weeding” of the data began in October last year.
Lib Dem justice spokesman Liam McArthur said: “Last year we revealed that Police Scotland had nearly a billion records of number plates, with the overwhelming majority belonging to entirely innocent motorists.
“It has been proven that ANPR cameras can be useful in locating stolen vehicles and identifying uninsured motorists, but we’ve not been given any evidence to show just how effective they are at doing that.
“I am glad to see that, after raising this issue, Police Scotland has finally taken action to delete over 500 million records and introduce a policy that will see old records deleted automatically.
“There are essential questions that remain unanswered, however; such as how Police Scotland was able to amass such an enormous surveillance network without a clear statutory basis or parliamentary debate. The SNP has a poor record when it comes to protecting people’s civil liberties, eroding and ending many rights and liberties.”
A Scottish Government spokesman said: “ANPR cameras are a useful tool to help detect, deter and disrupt criminality. Their use is a matter for Police Scotland, operating in compliance with all relevant legislation.”
Police Scotland referred Scotland on Sunday to their Freedom of Information response.