POLICE investigating the killing of a County Durham businessman in Central America believe he may have known his killer.

The body of Thomas Purvis, a 44-year-old security expert, was found by a friend in Costa Rica on Monday.

He had been stabbed to death and had 11 wounds in his back caused by a pointed weapon.

However, police say there were no signs of forced entry in his second-floor apartment in the fashionable Sabana Sur district of the capital San Jose and suspect that the victim may have let his killer into the building.

Mr Purvis, who moved to Costa Rica in 2002, is thought to have been killed over the weekend. He was last seen parking his car at 9am on Saturday, but could not be contacted over the weekend and friends finally persuaded the owner of the building to enter the apartment at 10am on Monday when he was found dead.

The businessman was believed to have been involved in selling microchips which can be implanted under the skin as a security measure and had been living at the address where he was found for the past nine months.

He is not thought to have relatives in the area.

Neighbours in the quiet residential area spoke highly of the dead man and were said to be in shock following the killing.

Investigators say there were no signs of robbery at the secure building and that his sports utility vehicle was still in its parking place on the ground floor.

Police spokesman Franciso Ruiz said: "It is possible that the cause of death was revenge because there are no indications of robbery."

British Embassy official Vicky Baxter-Amade identified the body at the scene. She added: "At this stage we are still waiting for more details from the police investigation."

A spokesman for the Foreign Office confirmed the death of Mr Purvis and said that next of kin have been informed.

He added: "Officials are providing appropriate consular assistance."

Mr Purvis is the fourth visitor to Costa Rica to be murdered in the past three years.