Police in England have confirmed that a house fire which killed six children was not an accident.
Derbyshire Police have said the blaze "was not accidental and initial indications are that it was deliberately set".
A teenage boy died in hospital this morning after the fire which killed five of his younger brothers and his sister.
Duwayne Philpott, 13, was in hospital since the blaze which claimed the lives of his sister Jade, 10, and brothers John, nine, Jack, seven, Jessie, six, and five-year-old Jayden.
The children were asleep upstairs in the house in Victory Road, Allenton, Derby, when the fire broke out at the semi-detached house in the early hours of Friday.
The children's father, Mick Philpott, made a "valiant" attempt to save them, police said.
A 28-year-old woman and 38-year-old man, both from Derby, were arrested by officers investigating the deaths but were yesterday released without charge.
Assistant Chief Constable Steve Cotterill said the investigation is at an early stage and that police have not yet had a chance to speak to Mr and Mrs Philpott properly.
Said to be the father of 17 children, Mr Philpott hit the headlines in the UK after demanding a larger house to share with his wife, Mairead, girlfriend, Lisa, and eight offspring.
He was dubbed "Shameless Mick" in 2007 for his benefit claims and refusal to get a job in a TV documentary by former Conservative MP Ann Widdecombe.
Mr Philpott is reported to have asked the city council to re-house his family, but the authority said they already had the biggest available council property in the city.
