10 year old feared murdered

Zahra Baker and her stepmother. Photo / AP

NEW YORK - The worst fears for Australian 10-year-old Zahra Clare Baker appear to have come true with United States authorities announcing they believe the shy, hearing-impaired amputee was murdered.

Chief Tom Adkins, head of North Carolina's Hickory Police Department, choked back tears when he announced that an Amber Alert issued at the weekend to find Zahra was cancelled and the missing person case had switched to a murder investigation.

Zahra's American stepmother, Elisa Baker, remains a suspect and has been charged with obstruction of justice for writing a fake ransom note demanding US$1 million ($1.33 million).

The note was discovered on a car parked outside the family's Hickory home.

"Elisa Baker admitted to writing the ransom note left on the vehicle," Adkinssaid.

Zahra's father, Adam, who has also not been ruled out as a suspect, was reportedly helping police and cadaver dogs search a wooded area at the end of a dirt road several kilometres from the family home.

Adding to police fears for Zahra, police dogs detected the smell of human remains on cars belonging to the father and stepmother.

Many questions remain unanswered about how Zahra, who moved to the US with her father two years ago after he reportedly met Elisa Baker on the internet, disappeared.

Adkins said that apart from Zahra's father and stepmother, no one can confirm seeing the girl in the past month.

He said "information" police had received pointed to an "inspector" visiting the home, but that had not been verified.

"We need the public to come forward if they think they have seen Zahra within the [one-month] timeframe," he said.

Zahra, who had her lower left leg amputated five years ago after a battle with bone cancer and used a prosthetic leg to walk, was born in the New South Wales country town of Wagga Wagga and spent time in Newcastle before moving north to Townsville and eventually North Carolina.

Her mother still lives in Australia.

Relatives have come forward with harrowing stories about how Zahra was allegedly treated at home. Brittany Bentley, married to Elisa Baker's nephew, told CBS TV Zahra was regularly beaten by Baker and locked in her bedroom for most of the day.

- AAP