West Yorkshire's Police and Crime Commissioner has given his support to a family which wants the deaths of a mother and her six-year-old son to be re-examined.
Denise Clough, 38, and her son Mark, were killed in a fire at their home in Broadstone Way, Holme Wood, Bradford, in April 2003.
The cause of the fire remains a mystery and Mrs Clough's family is calling for an impartial police officer to look at the case again.
Mrs Clough's younger sister, Diane Ellison, says the family believe the original investigation was flawed because officers focused their attention on Mrs Clough's son Andrew, who at the time had been a public nuisance.
An inquest, following the deaths, recorded an open verdict recorded an open verdict and was unable to pinpoint the cause of the blaze. It was told Andrew, who staged a burglary at his home, might have sparked the blaze when he cut a live cable, but investigators could not rule out the possibility the fire was started by a discarded cigarette or was an arson attack.
Mrs Ellison, 47, of Drighlington, said the family had been left with unanswered questions and would like to have closure. She said the family wanted all the evidence to be fully examined again in the hope of getting answers.
She contacted her MP, Labour's Ed Balls, who has written to West Yorkshire Police's acting Chief Constable, and Police and Crime Commissioner Mark Burns-Williamson, to "ensure the family's case has been investigated and is being dealt with in the proper way."
Mr Burns-Williamson said he had received a letter from Mr Balls regarding the concerns outlined by Diane Ellison.
The Commissioner said: "I will be discussing the letter and its contents with the Chief Constable to get a better understanding of what happened during the original investigation in this tragic case. I will also want to know whether there are any new developments that can be investigated and to hear from the Chief Constable any other relevant matters that the family ought to be aware of.
“I will be seeking reassurance on Mrs Ellison's behalf that her concerns regarding the original investigation are being taken seriously and will be looked at closely in the light of any new information or circumstances."