This article was reproduced with the kind permission
of the British Broadcasting Corporation
19 November 2007, 11:59 GMT
Robert Griffiths, 57, suffered serious burns in the blaze on Lowlands Walk, Askern, on 12 November. He died in hospital on Sunday.
Two other residents, aged 36 and 49, and a neighbour who tried to help suffered minor injuries.
Officers have issued an e-fit of a man they want to speak to about the fire.
They said the man was seen standing near the flats with another male a short time before the fire was reported.
Det Supt Richard Fewkes said the fire was deliberately started in or near the flats' bin store and then spread to the communal area of the four-flat block.
He said although Mr Griffiths manage to escape through the communal area, he suffered severe burns and the effects of smoke inhalation.
Detectives are appealing for witness to contact them.