The Scottish Prison Service (SPS) has denied it has set aside funds to cover claims arising out of alleged breaches of prisoners' human rights.
Slopping out compensation could be significant
But the annual accounts of the SPS revealed that it did have a contingency liability fund of £26m.
The denial on Thursday follows a case in which an inmate was given compensation because he was forced to slop out.
The Scottish National Party said the contingency figure was "staggering".
In April, Robert Napier was awarded £2,400, under the European Convention on Human Rights, for having to slop out at Barlinnie Jail in Glasgow.
The SPS has now estimated what its total liability could be for similar claims at £136m.
SNP Holyrood leader, Nicola Sturgeon, attacked First Minister Jack McConnell over the £13m which was taken from the prison service budget to establish the Scottish Drugs Enforcement Agency.
An immediate casualty of that decision was the programme which would have ended slopping out in Scotland by now.
Ms Sturgeon told BBC Radio's Good Morning Scotland programme: "It amounts to a huge proportion of the total prisons' budget in Scotland and yet it's been earmarked to pay out in compensation claims to convicted criminals.
"All because the Scottish Executive over the past few years hasn't bothered to get to grips with some of the big problems in our prisons, like slopping out."
And Tory justice spokesperson Annabel Goldie called on Justice Minister Cathy
Jamieson to appear before parliament and apologise to the taxpayers of Scotland
for "an entirely avoidable fiasco".
Ms Goldie said: "Ending slopping out would have cost £13m.
"The accounts of the prison service reveal the compensation bill could be
over 10 times that amount.
"That is a political scandal.
"Add to that the £500,000 spent defending the first claim and the massive
legal aid bill being run up by prisoners pursuing compensation and the full
extent of the slopping out scandal becomes clear."