The dog that killed four-month-old Archie Darby and left his brother with "life changing injuries" was owned by his aunt, who is "employed by the police", according to the Essex police and crime commissioner, Roger Hirst.
The baby died after being attacked in Colchester, Essex, on Thursday afternoon (13 October). His brother Daniel-Jay, who is 22-months-old, is still in hospital.
The attack happened at his aunt's house. She has been named by a number of media outlets as PC Clare Ferdinand, but the IBTimes UK was unable to independently confirm this.
Essex police and crime commissioner Roger Hirst told the BBC that the dog was "owned by the aunt of the children".
He also said that the woman "works for police", but could not clarify in which position and for which force.
Mr Hirst also said the family pet — believed to be a Staffordshire bull terrier-type — "didn't have any history" of aggression and "wasn't at all vicious".
Jade Rogers, the mother of the two boys released a statement on Friday 14 October which read: "Our beautiful sons Archie Joe Darby and Daniel-Jay Darby are so, so loved by us all and were such happy little loveable boys.
"It doesn't seem real that our little Archie Bum has gone to heaven and our little Daniel is in intensive care because of a tragic, tragic incident involving a dog attack. We have lost our gorgeous little four–month-old baby and our beautiful 22-month-old boy is currently being treated for his injuries."
She added: "Heaven has gained a beautiful little angel and he will be greatly missed by us all and our other little soldier is still fighting strong."
The dog has been put down with the owner's consent and no arrests have been made in connection with the incident which occurred around 3.10pm.
Scott Mills, 24, had earlier told The Guardian that the light brown dog that was removed from the house was "like a staffordshire bull terrier, but slightly more built".
"It was like it was a cross-breed," he said. "It was primarily staffordshire in its looks, but it was a lot broader."
He added: "It was totally calm coming out. There was no blood or anything on it. It didn't appear aggressive; it just appeared that it was being put on a lead to go for a walk. It just jumped in the back of the van and the van left."