A distraught family are baffled over the alleged murder of a grandmother who died after white spirits were poured through the letterbox of her isolated country farmhouse and set alight.

"Warm-hearted" community figure Lea Brooke, 81, perished from smoke inhalation when the blaze ripped through the plush cottage where she lived alone.

The family have now launched a fresh appeal for witnesses and information that might lead to catching the culprit - a month on from the callous killing.

Speaking at a press conference, son Howard, 45, and eldest daughter Suzanne, 61, made an emotional plea to help find their mum's killer.

And detectives echoed the family's calls for help and confirmed that they were clueless about a clear motive for the fire attack and had not come up with any suspects.

Det Supt Dave Pervin, who is leading the investigation, said he found it hard to believe that anyone would have targeted such a "lovely" woman - adding that police have considered another member of the family may have been the intended victim.