The father of four girls who were killed when their home was deliberately set on fire has died in hospital.
Police said they were not looking for anyone else over the deaths
Mohammed Riaz suffered severe burns in the blaze which killed his wife Caneze, 39, and daughters Sayrah, 16, Sophia, 15, Alicia, 10, and Hannah, three.
Lancashire Police said Mr Riaz, 49, died at Wythenshawe Hospital. Detectives had named him as their "top line of inquiry" in the murder hunt.
Accelerants were used to start the fire at the Accrington home on Wednesday.
Police had said the doors and windows were locked from the inside and whoever started the fire had not left the Trevellen Street house afterwards.
Mrs Riaz and the four girls died from smoke inhalation in their beds.
Mrs Riaz and her daughters died in their beds from smoke inhalation
Mr Riaz, who worked in a plastics factory, was pulled from the house by firefighters and was resuscitated before being taken to Wythenshawe Hospital, in Manchester. He suffered about 50% burns to his body.
A post-mortem examination is due to be held and the death referred to the coroner, a Lancashire Police spokesman said.
He added: "An investigation into the cause of the fire will continue, although all lines of inquiry would indicate that it was contained within the house.
"Police are not looking for anyone else in connection with their investigation."
Mrs Riaz had been described as "a pillar of the community".
Police had said they were looking into "a relationship breakdown" between the Mr and Mrs Riaz, who had been married for 20 years.
Mr Riaz was described by neighbours as a "good family man" who was very quiet and did not socialise other than at his local mosque.
The couple's 17-year-old son Adam is in hospital receiving treatment for leukaemia. He has been told of the deaths.
Special assemblies have been held at Hyndburn Park Primary School, where Alicia was a pupil, and at Accrington Moorhead Sports College, where her two elder sisters studied.
Mourners have laid dozens of floral tributes outside the house where the four girls and their mother lost their lives.
A book of condolence has been opened for the family at Accrington town hall.