THEY call the street the murder mile -where all manner of grisly crimes take place -but it is a scene welcomed by forensic experts.

The street is part of the redevelopment of an isolated County Durham mansion to keep it at the forefront of fighting crime.

Sixty years ago, some of the UK's most senior police officers gathered outside Harperley Hall to hail a new era in law enforcement - and yesterday, a new generation of experts gathered to welcome the redevelopment of the forensic training facility.

The leaders of Centrex, the Central Police Training and Development Authority, met to launch the hall's £10m redevelopment - aimed at maintaining its position at the cutting edge of forensic science.

The Georgian stately home, near Crook, hosts the National Training Centre (NTC) for Scientific Support to Crime Scene Investigation.

It is the UK's largest forensic teaching centre and its scientists have recently worked in Singapore, Botswana, Sierra Leone and Cyprus, as well as assisting in Sri Lanka and Thailand following the Asian tsunami disaster.

Keith Fryer, head of the NTC, said: "Harperley already has excellent facilities. With this redevelopment, it will be world class."

Perhaps the most interesting part of the redevelopment is the creation of the "murder mile" - a lifelike crime scene where investigation techniques can be tested.

Centrex will also build 80 en suite bedrooms, ten classrooms, a gym, a refectory, conference facilities, IT suites for imaging and fingerprint work, and specialist teaching laboratories.

A mortuary facility, a blood pattern analysis room and a centre for examining vehicles will also be set up.

Cutting the turf on the site, Hilary Armstrong MP, whose North-West Durham constituency includes the centre, said: "Policing has been transformed in the past ten years and this redevelopment is very important to its future.

"Citizens need to feel assured that there's a likelihood of crimes being detected. I'm delighted we have this centre in the North-East."

Carol Bernard, the chief executive of Centrex, said: "With almost every case that's tried now, you hear about the role of forensics.

"We recruit the highest quality individuals for police forensic work and it is essential that they are trained in an environment that matches their professional needs and standards."

Work on redeveloping Harperley Hall is due to be completed next year.

The expansion is expected to create jobs in the hospitality and catering sectors.

Control of Harperley Hall will pass from Centrex to the National Policing Improvement Agency on April 2.