A mother who torched herself and her two children in the family car had almost £20,000 in cash stashed in the boot.

Plastic bags stuffed with used bank notes were among a bag of washing, which had been dowsed in a highly flammable fluid in the back of the car.

Police are baffled why 23-year-old Nabeala Hussain, of Gresham Road, Middlesbrough, deliberately started the blaze, while she sat in the back to die with her son Danial, three, and her one-year-old daughter Salia Mariam.

All three died of smoke inhalation during the tragedy in her Vauxhall Astra last Thursday at around 4.30pm on Walpole Street, just round the corner from where she lived.

Officers know she soaked the passenger seat in fuel and lit a fire in the footwell but rescue crews put the fire out before it reached the boot.

Detective Inspector Karnail Dulku said: "Clearly she was trying to deprive someone of herself, her children and this money but where has it come from?"

"Her intention was to set fire to the whole car in one go and be burnt to death, which is a horrific way to go, but why did she have to take the children with her as well?"

Det Insp Dulku said the investigation into the three deaths had hit a wall of silence among Mrs Hussain's immediate family and friends.

"No one I have spoken to has given a plausible explanation as to why she would do this and the picture that is being painted that everything was fine simply isn't the case," he said. "This woman was so disturbed by something that she tried to set fire to herself, her children and a lot of money and someone must know why."

Mrs Hussain had no known criminal links, had never been involved with social services and had no medical history of depression.

Her husband Pervez Aktar, 30, who works in a Middlesbrough food factory, told police he cannot understand why his wife would do such a thing and yesterday he was still too upset to talk about what happened.

Det Insp Dulku said anyone with information owed it to the memories of the two innocent children to establish a reason for their senseless deaths.

If you can help call (01642) 303 126.