Nationalists have called for an inquiry into a project to upgrade the computer system which holds records of criminal convictions in Scotland.
The new version of the Criminal History System was supposed to have been up and running in early 2004 but will not now be ready until at least December 2006.
The SNP said the final cost of the project could reach around £10m.
The Scottish Executive said it was "disappointing" that initial work had not delivered the progress expected.
A spokeswoman said: "Ministers have never denied this. However, the executive has moved quickly to get a grip on the situation and has the right people and systems in place to deliver an effective criminal history system for justice services - and an efficient return for taxpayers money."
She said that it was not possible to give a "beginning to end" cost for the project, because it had no separate budget in its initial phase.
However, the cost to complete the current development work was £2.4m, she said.
More than £1m of that was on external technical consultants, the spokeswoman added.
There were also additional costs in maintaining existing Scottish Criminal Records Office computer systems to ensure there was no disruption to ongoing work.
The idea of the new system was for different parts of Scotland's justice system to be able to speak to each other as well as be in contact with databases such as the DVLA.
It was to be used daily by courts and police.
Scottish National Party MSP Stewart Maxwell called the matter "a complete disaster."
He said: "The police inspectorate said that the new system was central to modern policing.
"This was supposed to provide police forces with a real-time, up-to-date, modern criminal history system linked to all the new systems coming on stream and provide police on the ground with immediate information.
"If the inspectors think it is a centrally important system. Then it seems that to not have that system must have some detrimental impact on the way the police do their job."