DETECTIVES investigating the murder of a North-East housewife were pursuing new leads last night - more than 15 years after she was killed.

Ann Heron had her throat cut as she sunbathed in the grounds of her home on the outskirts of Darlington on August 3, 1990.

The killing of the mother-of-three at Aeolian House, near Morton Park, sparked one of the region's longest-running criminal investigations.

Earlier this year, Durham Police announced they had enlisted the help of one of the country's leading forensic experts to conduct a series of laboratory tests.

The expert, who has not been named, was asked to use the latest technological breakthroughs to scrutinise tiny samples, many of which had previously been beyond scientific analysis.

Police were able to view the crime scene in more detail than had previously been possible, thanks to the production of a computer 3D reconstruction of the house and grounds.

Retired detective Ian Phillips also completed a cold case review of the murder, sifting through 4,400 statements, examining 1,500 samples and looking at files on more than 7,000 people to produce his report.

Last week, Mrs Heron's husband, Peter, now aged 70, was charged with her murder.

He appeared before magistrates in Newton Aycliffe, County Durham, last Friday.

The retired businessman from Wishaw, North Lanarkshire, in Scotland, is due to appear at Teesside Crown Court on Thursday.

Police last week used the latest developments in the case to renew their appeal for anyone with information about the killing to come forward.

Last night, Detective Superintendent Dave Jones, who has been leading the investigation, said there had been a response from the public.

He said: "A number of calls have been received and, as a result, we are now developing some new lines of inquiry."

Police would not comment further on what those developments may be.

The Heron murder case is one of only two unsolved murders outstanding in County Durham.

The other is that of May Rebecca Thompson, who was killed in Spennymoor in 1952.