LANCASHIRE police due to travel to Spain at the end of this month in a bid to catch the killers of Blackburn grandad Joseph McCaughran have vowed: "no stone will be left unturned."

The 69-year-old died last June after tackling burglars at his holiday home in Torrevieja.

Mr McCaughran, a retired BT engineer, suffered severe head injuries when he was dragged along by the getaway car as he tried to stop them taking a camcorder containing film of his young grandson.

He died from a blood clot nine days later in a Spanish hospital. Lancashire Police were formally called in to investigate following Mr McCaughran's inquest in October, when a verdict of unlawful killing was recorded.

Senior investigating officer, Detective Superintendent Ian Jones, and Detective Inspector Bob Eastwood, of Blackburn Police, are to fly to Spain for a three-day visit to work alongside Spanish detectives in Torrevieja on May 27.

Mr McCaughran's widow, Sheila, of Walden Road, Blackburn, had complained that neither the English or Spanish authorities were doing enough to catch her husband's killers.

But Det Supt Jones defended his officers and said the hold-up had been at the Spanish end.

He said: "We could not go to Spain until the Spanish authorities invited us over. That invite came through a couple of weeks ago and we have made the necessary arrangements.

"Our presence in Spain reinforces the message to Mrs McCaughran that no stone will be left unturned and hopefully the Spanish detectives will be receptive to our visit but at the end of the day it is their investigation and their decision."