The failure of an £8 million IT system designed to aid Scotland's fight against crime may never be fully investigated after it emerged the national spending watchdog has no powers to scrutinise the police organisation behind the project.

The Herald reported last week a state-of-the-art police computer system, overseen by the Association of Chief Police Officers in Scotland (Acpos) has been abandoned before being put into service.

The £7.7m Common Performance Management Platform aimed to put the crime figures for the forces on an equal footing for detailed analysis. It should by now have saved the country's eight police forces more than £30m, but it cost at least five years of officers' time and failed to deliver.

It was thought Audit Scotland could investigate the management of the project but the spending watchdog confirmed Acpos is not accountable to them – a concern the watchdog and others have raised in the past.

Politicians last night criticised the lack of accountability for a publicly funded project.

Scottish Conservative justice spokesman David McLetchie said: "This situation is absolutely ridiculous. Acpos spends, and in this case has wasted, millions of pounds of taxpayers' money, and as a result their actions have to be subject to scrutiny. Given the money wasted on this initiative, this ludicrous issue of auditing has to be reviewed."

Lewis Macdonald, Scottish Labour's justice spokesman said: "Somebody must be responsible for the mistakes made, so it is appropriate to examine how accountability and transparency can be enhanced. I will be raising this with the Justice Secretary because it is critical he gets a grip of this situation."

An Audit Scotland spokes-man: "Acpos is a limited-by- guarantee company, which we do not audit.

"We have previously stated we believe Acpos is helping make important strategic decisions about Scotland's policing, and thus the use of resources, but that the accountability of Acpos is unclear.

"Regarding ICT [information and communications technology] projects in the public sector, we will be publishing a report at the end of August looking at the management of some specific public sector ICT programmes.

"We will be reporting some findings and making recommendations about how the management of ICT projects in the public sector could be improved."

Chief Constable Derek Penman, who is leading on ICT reform for Acpos, said: "Acpos is in discussion with stakeholders to explore options for a review of the Common Performance Platform Project.

"Any lessons learned will be used to inform future projects. Acpos is committed to making the findings from any review available for public scrutiny."