Police have arrested a 69-year-old man on suspicion of murder relating to the death of postmistress Una Crown 11 years ago.
The man, from Wisbech, was arrested this morning and remains in custody at Thorpe Wood Police Station in Peterborough.
Mrs Crown had her throat slit and her body torched before she was found lying in a pool of her blood and surrounded by burnt newspaper.
Officers were called to her home in Magazine Lane, Wisbech, Cambridgeshire, after family members and a neighbour discovered the body on January 13, 2013.
Mrs Crown’s wedding ring, front door key, and £40 were missing.
Police initially thought she had accidentally set herself alight, and later apologised after a post-mortem revealed she had died from stab wounds to her neck and chest.
Una Crown, 86, whose throat was slit before her body was torched
The last image of Una Crown alive – CCTV taken at Wisbech Tesco on January 11 2013
Mrs Crown had been seen alive two days before and had spoken to a friend over the phone at about 5pm on the Saturday.
She also appeared in good spirits as she went shopping on the Friday – with CCTV capturing her leaving a store with her trolley.
Her death was initially treated as unexplained but, after a post-mortem examination concluded Mrs Crown died from stab wounds to her neck and chest, a murder investigation was launched.
Mrs Crown’s clothing had been set alight, in an apparent attempt to disguise her injuries and destroy evidence, but the fire did not spread to the rest of the house.
Two attending police officers had initially concluded the death was not suspicious, thinking the pensioner had died from a heart attack after her clothing had accidentally caught fire due to a faulty hob ring which she had tried to put out with a tea towel.
They also believed the slits to her throat were caused by the pressure from a scarf as her body hit the floor.
Una Crown’s bungalow in Wisbech, Cambridgeshire
The bungled initial investigation meant that family members were allowed back into the property and key evidence may have been destroyed.
In January, Detective Superintendent Iain Moor, from the Bedfordshire, Cambridgeshire and Hertfordshire Major Crime Unit, said: ‘It has now been 11 years since Mrs Crown’s tragic death and we still seek justice for her family.
‘Last year we appealed for help on national television with a reconstruction of events. It is incredibly positive we were able to reach such a large audience, but we continue to seek opportunities for new lines of enquiry.
‘We also continue to re-appeal to the public for information and keep the case in people’s minds.
‘I am urging anyone who has information but has not yet come forward, to do the right thing and get in touch.
‘Any information, no matter how small or insignificant it may seem, may be key to solving this investigation and finally getting justice.’