MSPs have been paid more than £1m by the taxpayer to purchase second homes in Edinburgh, it has emerged.
The scheme was approved by the parliament
BBC Scotland has confirmed that the money was claimed by 38 politicians.
Socialist MSP Tommy Sheridan has called for an official inquiry into what he calls widespread abuse of the Edinburgh Accommodation Allowance.
But a spokesman said the present scheme was approved by the Scottish Parliament in 2001 and that the regulations had been followed in every case.
The allowance enables MSPs who live more than 90 minutes' journey from the Scottish Parliament to have subsidised mortgages for second homes in the capital.
They can claim up to £10,600 per year towards housing expenses.
Mr Sheridan called for an investigation into three former Scottish National Party MSPs who he said had made more than £100,000 profit after selling their subsidised flats.
They had claimed mortgage allowances of £90,000 before selling up.
Tommy Sheridan says the rules need changed
Another four MSPs, who have now left the parliament, have kept flats with a current market value of nearly £500,000. They claimed subsidies of almost £130,000.
A parliament spokesman said the regulations had been followed.
However, Mr Sheridan said the rules need to be changed.
The Socialist MSP has already accused Scottish Executive ministers of using the accommodation allowance scheme to cash in on Edinburgh's property price boom.
Since 1999 the taxpayer has paid 11 executive ministers almost £340,000 towards the costs of the second homes they have bought in the capital.
The average house price in the city has almost doubled over that period.
Rented a flat
A number of ministers have bought flats, sold them and then used the profits to buy more expensive properties.
However, former Deputy First Minister Jim Wallace - one of those named by Mr Sheridan - said the accusation of property speculation was "rubbish".
He said he would have been costing the taxpayer "considerably more" if he had rented a flat or stayed in a hotel.
And he stressed that the allowance related to the interest on the mortgage, not any capital repayment.