Adeel Khan, 44, has been charged with three counts of murder and two of attempted murder, three counts of manslaughter and 17 charges relating to the damage to property caused by the fire in Darling Street on September 4.

One of those charges is setting fire for a financial gain, with police alleging the fire was deliberately lit.

Bianka O'Brien, 31, her baby son Jude and their neighbour Chris Noble, 27, all died in the fire.

Three others were injured, including Mr Khan, who was discovered by fire crews trapped underneath a commercial fridge. He was charged by detectives while being treated for his injuries in Royal Prince Alfred Hospital.

On Tuesday, Central Local Court was told Mr Khan is in the Long Bay prison hospital and is too unwell to appear via video link.

He was represented by solicitor Michael Vassili and barrister Mark Fozzard.

Crown Prosecutor Katharine Jeffreys said the investigation is "large" and the brief of evidence already contains more than 3000 pages of material.

The fire tore through the convenience store, which Mr Khan had owned for only months, the neighbouring mobile phone shop and the residential units above in the early hours of September 4.

Mr Khan will reappear in Central Local Court on January 27.