Detectives believe they have made a "significant breakthrough" in the hunt for the killer of a former Scots-based grandmother whose body was found as she house-sat for friends.

Artist Valerie Graves was found with significant head and facial injuries at a house in Smugglers Lane, Bosham, West Sussex, on December 30, where she was staying with her family while the owners were away.

Ms Graves, who had graduated in textile design from Heriot-Watt University seven years ago, had only recently moved to the south coast from Jedburgh, in the Borders, where she had lived for about 10 years. She had set up her own crafts studio at Harestanes, near Jedburgh, before the move south.

Detectives believe the 55-year-old was attacked in her bed during the night by an intruder using a hammer. She died as a result of severe head injuries.

Now a limited DNA profile for the suspect has been obtained by forensic scientists, which means detectives can start requesting voluntary DNA samples to eliminate males from the investigation.

Officers will be targeting men who live and work in the Bosham area, either permanently or as migrant workers, and also be speaking to visitors in the area to eliminate them from the investigation.

Detective Superintendent Nick May, of the Surrey and Sussex Major Crime Team, said: "This is a significant breakthrough for the investigation. Although this profile is not suitable for a search on the National DNA Database, it does indicate the suspect is male.

"Anyone who provides us with a DNA sample could now be eliminated from the investigation. The profiling will involve taking a swab from the mouth and fingerprints from each individual.

"We are stressing that if anyone has any concerns or suspect they may know something, they can talk to our officers or Crime­stoppers anonymously. We can rule out people whose names are suggested as being responsible for the murder by comparing their DNA with the sample.

"It is important for the public to understand we will only use the samples obtained to check against this particular crime and their DNA profile will not appear on any database. Legal safeguards are in place to ensure we do not use them for any other purpose.

"Without the public's assistance this process would take many months to achieve."

Ms Graves was well-liked, with two grown-up children and two grandchildren, and had moved to England to help care for her mother in Bracklesham Bay, West Sussex.

At the time of Ms Graves's death Fiona Waldron, head of the School Of Textiles And Design at Heriot Watt University in Galashiels, Selkirkshire, said: "She was a creative person with a wide range of artistic interests and will be much missed."

Douglas Hunter, who also had a studio at Harestanes, said Ms Graves was well-liked, popular with her neighbours and a respected member of the artistic community.

"She had won awards for various projects," he said.

Ms Graves's son, Tim Wood, and daughter, Jemima Harrison, also paid tribute while calling for information which may find her killer.

Mr Wood said: "My mum was much loved and will be sorely missed by the whole family. She was a free spirit who enjoyed her life and was a talented artist.

"She had lived in Scotland for about 10 years, a place she loved and which inspired her passion for art."

A reward of up to £20,000 is being offered jointly by Sussex Police and Crimestoppers for information leading to the arrest and conviction of Ms Graves's killer.