A MAN died following a house blaze started by a firework pushed through his letterbox, police said yesterday.

Arthur Lonsdale died in hospital of respiratory failure caused by smoke inhalation.

Detective Superintendent Steve Wade, who is leading the murder inquiry, said: "We now believe this fire was caused by a firework pushed through the letterbox at the rear of the house."

The 52-year-old former locksmith of Westerham Close, Witherwack, Sunderland, died on Saturday after the fire last Thursday.

Det Supt Wade said: "Forensic scientists say the firework got in and bounced its way around the hall and then got lodged.

"A catflap in the back door has provided an oxygen supply, which ignited the flame which then spread up the stairs and throughout the house.

"By the time the fire brigade arrived this was a very, very serious fire, flames were shooting out of the roof."

He said the fire was caused by a Little Brother rocket made by Global Fireworks Limited, of Leeds.

"Mr Lonsdale was asleep on the settee and awoke to find smoke filling up his home. He tried to get out of the front door, which was locked, but was quickly overcome.

"Fire officers who forced the door found him lying in the hallway."

He said: "We are not looking to prosecute anyone for selling these fireworks.

"But anyone who did this as a prank should know that putting a firework like this through somebody's letterbox into a house is going to cause some serious damage.

"Whether the person who did it foresaw the consequences of what they were doing is open to question, but these things are lethal.

"Mr Lonsdale had very high levels of carbon monoxide in his blood.

"He made some little recovery on Friday evening, enough to talk to his neighbours and friends, but he could not say who was responsible."

Mr Lonsdale, known locally as "Arky", provided a self-funded cat refuge for abandoned animals.

Six cats he was caring for also died in the fire.

Anyone with information is asked to call the incident room on 0191-454 7555, extension 65017, or Crimestoppers on 0800 555111.

* Two juveniles arrested in connection with the fire remain on police bail.