Police allege Brett Anthony Crawford, 34, forced his way into a Bateau Bay aged care facility on the Central Coast just before 1am on November 15.

Once inside, the man allegedly assaulted and sexually assaulted a 90-year-old woman in her room, causing her serious injuries.

She was rushed to hospital after managing to raise the alarm with staff.

Police confirmed the woman sadly died in hospital this morning, and her family have asked for privacy at this trying time.

A strike force - codenamed Easterbrook - was launched by the State Crime Command's Sex Crimes Squad in the wake of the horrific allegations.

Crawford was taken into custody on the night of November 20 in a dramatic end to a days-long manhunt and urgent public appeal for help spanning the Central Coast and Newcastle.

Strike force detectives homed in on Crawford at Caves Beach, and were backed by police from Tuggerah Lakes and Lake Macquarie, the regional enforcement squad and the force's transport command.

Crawford allegedly raced out the back door of the home as police entered and jumped a fence before he was arrested.

He was taken to hospital with an arm injury.

Belmont Local Court heard he would undergo a forensic mental health assessment while behind bars, after he was refused bail on a string of serious charges.

At the time of Crawford's arrest, police believed there was no link between him, the elderly woman, or the nursing home, and alleged the attack was random.

Sex Crimes Squad commander Detective Superintendent Jayne Doherty said after Crawford's arrest that the alleged victim had been "very traumatised" and suffered "very severe wounds to her arms".

She said officers believed the woman's cries for help had been muffled by bedding, and alleged her assailant had pinned her to the bed and sexually assaulted her.

"As you can understand, being elderly her skin has torn quite significantly where pressure was applied," she said.

The woman suffered arm, leg and head injuries.

"We understand that the community will be in uproar over this type of offence," she said.

Strike Force Easterbrook investigations continue.

A report will be prepared for the coroner.