Cases of multiple abuse where police are unable to identify individual suspects and bring charges will be the subject of a Home Office rethink after a pensioner died following a catalogue of horrific injuries.

Home secretary David Blunkett has called for a review of policy on cases where police believe a crime has been committed but are unable to decide which individual should be charged. The move follows an inquest into the death of 78-year-old Margaret Panting who suffered burns, bruises and cuts to her body after leaving sheltered accommodation, where she had been in reasonable health, to move in with her son-in-law and his three teenage children. She died five weeks later.

Pathologists told the Sheffield inquest that Panting's injuries were caused deliberately, but could not say that they directly resulted in her death as she suffered a heart condition and had pneumonia.

Coroner Christopher Dorries recorded an open verdict after dismissing an explanation from relatives that the injuries were accidental. He said it was clear Panting had been abused by a person or persons whose identity could not be determined. But it could not be proved beyond reasonable doubt that the injuries had led to her death.

Police said that following a detailed investigation two arrests were made, but there was insufficient evidence to bring a prosecution.

A spokesperson for the home secretary said Blunkett could not discuss individual cases but was "concerned" over issues raised in cases like that of Panting as well as others, including some child abuse investigations. "He is very concerned about cases where, because it is not apparent who may be liable for criminal charges within a group of people, the police are unable to take matters further." Officials had been asked to look at possible ways to "do more to be able to equip the police to further their investigations".