Perth and Kinross Council is due more than £24 million in unpaid council tax, new figures have revealed.
The study of authorities shows how much each area is owed since the tax was introduced in 1993.
When the total deficit is broken down per person, Perth and Kinross is due £161.37 per head.
The combined totals due for Perthshire and Fife come to around £94 million.
In 2015-16, for Scotland as a whole, the total amount of council tax billed was £2.115bn, of which £2.025bn was collected.
According to a Scottish Government spokesman in-year collection rates across the country have improved steadily from 87.2 per cent in 1998-99 to 95.7 per cent in 2015-16.
Mid-Scotland and Fife MSP Murdo Fraser said: “This is a staggering amount of money to be left unpaid.
“Where people are wilfully avoiding paying council tax, local authorities in both Perth and Kinross and Fife must clamp down on them.”
Mr Fraser said: “For those that are struggling to pay I would encourage them to seek help from their local council as they could be due assistance in the form of council tax reduction.
“Authorities across Scotland are experiencing serious spending constraints and I would encourage them to up their efforts to claw back missing tax before considering hiking the rates for existing bill payers.”
He added: “Council tax isn’t something people can just decide not to pay, it’s crucial in funding services upon which everyone depends and the Scottish Government has a role to play in helping local authorities chase up unpaid tax.”