Strike force detectives seized a Mazda from a home at Gymea under a Coronial Order last Tuesday. Picture: NSW Police
NSW Police have seized a car that once belonged to William Tyrrell's foster grandmother from a home 375km south as the search for the missing boy's body continues.
The silver Mazda hatchback was seized from a home in Gymea, in the Sutherland Shire, under a coronial order on November 9.
It is being held in a secure facility where forensic examinations and analysis is under way – a process detectives say will take "several weeks".
News.com.au understands the car belonged to William's foster grandmother at the time he went missing. She died in March, aged 88.
The person who owned the car when it was seized is not believed to be related to the disappearance of the 3-year-old in 2014.
News.com.au understands police are investigating whether the vehicle was used to move William's body after his death.
NSW Police also released new images of the forensic examinations taking place at William's foster grandmother's home in Kendall, where he was last seen.
Authorities remained at the house on Tuesday night and are understood to have kept guard overnight as detectives continue their hunt to solve the mystery of what happened to the little boy.
Forensic examinations by Strike Force Rosann are expected to continue today, with officers continuing to focus their attention on an area below the second-storey balcony, where detectives are probing a theory the boy may have fallen to his death.
Reports of the new theory come as information was revealed about a suspect in the boy's disappearance.
The suspect, who cannot be named for legal reasons, recently had a child removed from her custody and had an apprehended violence order taken out against her.
It is understood the woman had previously been spoken to by police but was never pursued as part of the investigation.
In new footage released overnight, a number of officers appear to be using metal detectors in the garden and removing plants and other debris.
A cadaver dog had earlier been used to comb through the garden bed.
The images come from Strike Force Rosann, who have been working under the premise that his disappearance was a result of human intervention.
Late night images reveal investigators continuing to search the garden overnight, focusing on a specific area where police had earlier dug and sprayed luminol, a substance that shows traces of blood.
In the pictures, investigators can be seen combing through the garden and the outside walls of the home with a bright blue light, which would illuminate if blood was apparent.
Video reveals police spraying more of the area and scanning photographs of items with the chemical.
Police have also been scanning an area of bushland about 1km from the house.
Shortly before 10.30am on September 12, 2014, William, then aged 3, was playing in the yard of his grandmother's home in Kendall, when he disappeared.
At the time, hundreds of residents and emergency service workers and volunteers searched homes, forests, creeks and paddocks throughout the rural township, but William could not be found.
"The Strike Force Rosann team returned to Kendall with local detectives and specialist forensic officers to have another look at the residence where William was last seen, as well as other areas nearby," Detective Chief Inspector David Laidlaw said last week.
"Further information has since come to light, as part of our ongoing review of the materials gathered by investigators since the moment William went missing seven years ago.
"As our team continue to conduct inquiries and explore all avenues of investigation, our focus has been identifying if anything has been missed, or if there are any details – no matter how small – that need to be clarified.