Police hunting the killer of former Keighley woman Yvonne O'Brien have widened their hunt from the holiday island of Majorca to mainland Spain.

They now believe the person who tortured, stabbed and sexually assaulted the 44-year-old may have fled during the 13 hours that her body lay undiscovered on Monday.

And they are trying to trace the origin of threatening letters found in Mrs O'Brien's rented home in the resort of Puerto d'Alcudia.

Jason Moore, editor of Majorca's English-language newspaper the Daily Bulletin, said: "She was murdered at about 4am and the body was discovered at about 5pm and police think the killer may have left the island in that period.

"Inquiries have so far drawn a blank on the island and they suspect the killer is now on the mainland.

"But they have found some threatening letters in the house which were written in English and posted in London - although we don't know what they say or who they were from."

Humphrey Carter, also of the Daily Bulletin, said police had been ordered to keep silent about the case because it had attracted international attention.

"It is the first type of murder like this they have had on Majorca and it has put the island under the spotlight with the British Press and with the German media because there are a lot of Germans living here," he said.

Detectives in Buckinghamshire, where Mrs O'Brien lived before divorcing her husband and moving to Majorca about three years ago, have been involved in preliminary investigations.

A spokesman said: "We have registered the fact we will assist if we can, but basically it needs a formal request from the Spanish authorities and we have had no direct link as yet."

Mrs O'Brien had been stabbed more than 40 times, her throat had been cut and her body had been mutilated.

The words "Love, Sex and Peace" had been scrawled in her blood on the walls.

Islanders said she was well known for her drinking and unorthodox lifestyle.

Police have arrested and interviewed two men but they have been released without charge.

Her brother, Philip Graham, who lives in Keighley, said he and his wife Tina were now planning to emigrate to Majorca.

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