William Tyrrell: police seize car in Sydney as search continues at Kendall home

New South Wales police have seized a car as they continue to comb a mid-north coast property and surrounding bushland for the remains of missing three-year-old William Tyrrell.

The renewed search for vital clues in the baffling seven-year mystery is now in its third day as detectives returned to the property where he disappeared.

Police on Tuesday dug up the garden at the Kendall home, with a mechanical sift brought on to the property, and sprayed luminol, a chemical that detects traces of blood, during the night.

In nearby bushland, volunteers cut down trees to help in the search.

Asked if police were investigating whether William died after falling from a balcony at the house, the police minister, David Elliott, said every option was being considered.

The police commissioner, Mick Fuller, has confirmed there has been a significant breakthrough in the case, saying he is confident police will solve the mystery of what happened to William.

A $1m reward for information on the case still stands.