Anthony and Linda O'Malley were looking for property

Tony and Linda O'Malley, from Llangollen, went missing in September 2002 while looking for a holiday home in Benidorm.

A spokesman for police in Valencia said two bodies had been found and four people had been arrested.

The bodies were discovered in mountains near the industrial town of Alcoy, approximately 12 miles inland from Benidorm.

A British Consulate official in Alicante said police were "as sure as they can be" that the bodies were those of Mr and Mrs O'Malley.

Police in Valencia are expected to hold a press conference on Wednesday to release further details of the case.

The discovery of the bodies has changed the missing persons hunt into a murder inquiry.

A North Wales Police spokesman said: "North Wales Police have been working in close co-operation with the Spanish police investigating the disappearance of Linda and Tony O'Malley.

"The Spanish police are leading a murder investigation and North Wales Police are assisting with this investigation."

Self-employed car salesman Tony O'Malley, 42, and his 55-year-old wife Linda, a store manager, should have returned home after a fortnight in Spain looking at property.

They had seen a house at Villajoyosa, near Benidorm, and after their disappearance it was discovered that expensive cash purchases had been made from their credit card and thousands of pounds had gone from their bank account.

Members of the O'Malleys' family said the huge level of spending during that week and the absence of a phone call home were completely out of character for the couple, who are originally from Liverpool.

Danny Collins, senior news editor at the Costa Blanca News, said the police had had a search warrant for a property in Alcoy.

The bodies were found in mountains near Alcoy

"Two bodies were found buried in the basement of the property," he told BBC Radio Wales.

"Two men and two women were arrested at the time and are now in Valencia."

Mr Collins said what he called "the Valencia connection" became apparent about a month ago.

"The credit card of Anthony O'Malley had been used in the Valencia area on the 14 and 15 of September.

"We also knew that 28 CCTV tapes were taken back to Wales by the North Wales Police on a visit here and these have been studied very closely.

He added that there was a "huge amount of sympathy" for the O'Malleys' family among the expatriate community in Spain.

A recent Week In Week Out documentary for BBC Wales followed Mr O'Malley's brother Bernard O'Malley on his journey to Spain as he attempted to uncover any clues the police may have missed.