A VITAL police IT project that has faced delays and contractual wrangles has been hit with a further setback after its initial launch date was once again put back.

The i6 project, which will see a single system operate across the country, has been described by Police Scotland as the "largest and most significant transformational change ever undertaken by the service", replacing 135 existing IT and paper-based systems and providing officers with a state-of-the art crime fighting tool.

However, serious concerns have been raised over i6 by MSPs, after it became apparent that Police Scotland had become embroiled in a dispute with the contractor, Accenture, and a series of key targets were missed resulting in the national roll-out date being put back by nine months to September next year, which will be three-and-a-half after the launch of the single force. A deal was recently agreed to spend £6m on replacing 26,000 computers and monitors ahead of the upgrade.

Although the force has insisted that it remains on course to hit the final deadline, it has emerged that the first "go live" date has been pushed back from July to September this year, after it took longer than expected to design the system. It means that there will now be 12 months between the initial launch of the system and full roll-out to 20,000 officers and staff, a shorter period than originally planned.

Deputy Chief Constable Neil Richardson, who is due appear before the Scottish Parliament's Justice Sub-Committee on Policing today to discuss i6, said sticking to the original timetable would have presented "an intolerable level of risk" to the programme as a result of "aggressive scheduling and unachievable timelines".

Labour MSP Graeme Pearson, a former assistant chief constable and a member of the committee, said he was concerned to learn of yet another delay in the project.

"If it means it will eventually be delivered in an effective and timely manner, well and good," he said. "But behind all this is a rumbling worry that there is a problem in delivering i6 and that needs to be resolved.

"This is absolutely key in reforming the police service in Scotland. Until it is in place, the general benefits of the reformed police service will not be delivered. Let's hope this is the last delay we face."

Accenture is being paid £39m to provide the new integrated i6 system, with costs rising to around £60m when other factors - such as staff redundancies - are taken into account.

Police Scotland has said that despite the first go-live date for the new system, which will cover 80 per cent of the police's operational activity, being put back the incremental roll-out could be accelerated with measures such as staff training to be completed within a tighter timescale.

Independent MSP John Finnie, who also sits on the Justice Sub-Committee, said: "The public sector is littered with with examples of significant IT contracts going wrong, and there has already been a delay in this case. We are very keen that there is no detrimental impact on operational policing which is the rationale for this all singing, all dancing system. We want to ensure that this is in place within the agreed timeframe and it's clearly important - for a number of reasons - that targets are met."

Police have admitted that current systems, which were used by the previous eight forces that merged to create Police Scotland, are "complex, inefficient and not designed to fully support the needs of a modern national police force". The replacement, its advocates claim, will free police up to spend more time fighing crime, while they will be able to make enquiries more efficiently as they will not have to search multiple systems for information.

Chief Superintendent Niven Rennie, President of the Association of Scottish Police Superintendents, said: "We have a poor computerisation structure at present, particularly in the West of Scotland. The sooner we have this in place the better, but I would rather it was done correctly than rushed through."