Scotland's biggest police force has still to sign off on the quality of forensic science services, 10 months after they were transferred to a new centralised support agency.

Strathclyde Police yesterday confirmed that it was still in discussions on a service level agreement with Scottish Police Services Authority or SPSA, the body that has been in charge of all the country's crime labs since April last year.

The force's most senior officers, and colleagues from elsewhere in Scotland, have been highly critical of the SPSA in private and public, warning of creeping centralisation.

SPSA was set up to provide back-office services, such as forensics and information technology, but doubts have been cast by some officers on both its accountability and ability to deliver its promises.

The agency is due to take over all police computer systems on April 1. However, as revealed in The Herald last week, no Scottish police force has agreed a service level agreement for IT, with just six weeks left before transfer.

Strathclyde is the only force to still sign a service level agreement with SPSA on forensic science.

Both parties last night insisted there was no problem with the work of the labs, although they clearly differ on what standard should be imposed on the service.

A spokesman for the Glasgow-headquartered force said: "Strathclyde Police continues to discuss the content of the Service Level Agreement with SPSA. At this time, we have suffered no detriment of service during the discussions."

Strathclyde, which polices around half the Scottish population, has traditionally enjoyed some of the best services in the country, including its crime lab and IT department.

The Herald earlier this month discovered that senior Scottish Government advisers were suggesting transferring more police functions to SPSA, including motorway policing, serious fraud investigation and air support.

Steve House, Strathclyde's Chief Constable, bluntly told his police board this would hurt frontline policing in the west of Scotland.

His force, for example, is the only one in the country with its own helicopter.