Margaret Peel was bludgeoned to death in the village shop she ran in the hamlet of Fewston, on the border between North and West Yorkshire, in 1938.

Her husband, a labourer and caretaker at the village church, was arrested but found not guilty of her murder at Leeds Assizes.

Since then the case has remained unsolved.

But now Detective Sergeant Paul Fletcher of West Yorkshire police has decided to investigate the murder in his own time.

He believes new investigative methods and modern techniques such as DNA testing could uncover fresh evidence to solve the crime.

Det Sgt Fletcher is now trying to trace descendants of people who lived in the village at the time, but has few other leads.

A wheelbrace, which may have been the murder weapon, was found in a nearby reservoir after the murder.

But it could not be linked to Mr Peel, whose 37-year-old wife suffered 11 head wounds and was found by a teenage girl who called in for groceries.

Mr Peel died five years after his wife when he was hit by a car as he cycled on patrol duties for the Home Guard.