NSW prisoner questioned over Tyrrell case

A person of interest has been questioned by detectives over William Tyrrell's disappearance before police launched a fresh search of the property where he used to live on the NSW mid-north coast.

Frank Abbott is expected to testify at the ongoing NSW inquest into the suspected abduction of three-year-old William when it resumes in March.

Abbott was questioned in late 2019 by police while he was behind bars for an unrelated conviction, a source has confirmed. He was not charged.

He was interviewed under a Section 25 order which allows an inmate to be temporarily transferred to be questioned by law enforcement officers.

NSW Police this week searched a sawmill on Herons Creek Road where Abbott lived at the time William vanished from nearby Kendall.

The property searched was the same one police, sniffer dogs and SES personnel scoured in August 2019.

No one has been charged in relation to William's disappearance.

Hundreds of people have been dubbed "persons of interest" during the investigation and a case detective admitted during the inquest there's "a very low standard to meet in order to become a person of interest".

Counsel assisting the coroner Gerard Craddock SC in August stressed that any suggestion those called to give evidence were suspects was "simply wrong".