Jane Longhurst was last seen in Brighton on 14 March

On Tuesday officers were scouring the Ashdown Forest, in the north of the county, for any sign of Jane Longhurst who was last seen on 14 March.

A number of sites across East and West Sussex were also going to be searched, a police spokesman said.

Since her disappearance, Miss Longhurst's mobile phone has been switched off and there have been no transactions on her bank accounts or credit cards.

Reliable and dependable

Sussex Police have now turned their missing person's inquiry into a major crime investigation called Operation Keen.

At a press conference, Detective Chief Inspector Steve Dennis, who is leading the inquiry, said: "We believe that she has been abducted and probably killed - as such this is now a major crime inquiry."

Officers are also trying to trace a woman and child aged about 12, who were walking near Miss Longhurst when she was last seen.

The dark-haired girl skipped around her as she walked towards the door of her flat.

Police said the girl was wearing cerise pink and white clothes and the woman, possibly the girl's mother, was about 5 ft 5 in, with dark hair and was dressed in dark clothes.

Originally from Reading, Miss Longhurst lives in Shaftesbury Road in Brighton with her partner Malcolm Sentance and works at Uplands School in the city teaching children with special needs.

She is described as stable, reliable and dependable and is a member of a local orchestra in Lewes.