The seven-year-old, who had autism, was found dead in her bed at her Hawks Nest home, on Saturday November 3.

She weighed just nine kilograms at the time of her death, a healthy weight for an 18-month-old.

She is believed to have starved to death.

Police homicide detectives are leading the investigation into Shellay’s death.

The team of detectives attended the Hawks Nest home on Friday, where Shellay died.

They are investigating the circumstances surrounding her death.

A spokesperson for the State Crime Command said on Monday the investigation was ongoing.

No further details were released.

The family moved to the Hawks Nest area on August 31.

Shellay’s former Sydney neighbours say they repeatedly contacted welfare authorities with concerns about the girl who never attended school.

They say she spent days in a room littered with rubbish and excrement.

The NSW Department of Education confirmed Shellay had never attended school, saying options for her education had been put to her parents.

Shellay’s father Blakely Ward has denied any wrongdoing.

Health experts have confirmed that autism can affect growth rates in children.

In the days following Shellay’s death the NSW Department of Community Services (DOCS) has come under fire for not acting on the situation.

NSW Ombudsman Bruce Barbour released a statement on Friday saying his initial inquiries into Shellay’s death revealed DoCS had received a “substantial” number of reports relating to Shellay and her siblings over 14 years.

Mr Barbour said his investigations would also now examine three other government departments and two area health services.

The Department of Housing, Department of Education and Training, and the Department of Ageing, Disability and Home Care will be asked for information about the extent of support they offered Shellay and her siblings.

The revelations about the youngster’s family came as the NSW government announced a commission of inquiry to examine child protection.

It will be headed by former Supreme Court judge James Wood, who oversaw a royal commission into police corruption.

Community Services Minister Kevin Greene has refused to divulge any further information about the case due to legal advice against commenting during the police investigation.