New South Wales police forensic investigators are examining “anomalies” in the grounds of the former home of Sydney woman Lynette Dawson, who has been missing since 1982.

Homicide squad commander Det Supt Scott Cook said officers will conduct a “hand dig” and feed the resulting material into a sifter.

“We will go until we hit rock,” he said.

Police began digging at the property at Bayview on Sydney’s northern beaches on Wednesday and expect to be there for at least five days.

Lynette Dawson was last seen in January 1982. Photograph: NSW Police/AAP

Four areas around the home and in the backyard near a clothesline and pool – which were there before she is believed to have been murdered – are being examined.

These are areas that have been looked at before but not with the new technologies available today.

“Previously, when we conducted examinations here, there was a number of anomalies in the ground,” Cook said. “They were inspected previously. We’ll revisit them.”

In 2015, detectives from the unsolved homicide unit established a strike force to reinvestigate the circumstances surrounding the 1982 disappearance and suspected murder of the northern beaches wife and mother.

The case has been the subject of a highly popular podcast, The Teacher’s Pet, by the Australian newspaper. Dawson, a 33-year-old mother of two girls, was last seen in January 1982.

Dawson spoke to her mother on the evening of 8 January 1982, while she was at home with her husband, Christopher Dawson.

She made plans to have lunch with her mother the following day at Northbridge Baths, but did not show up. She was reported missing on 18 February 1982 by her husband.

After two coronial inquiries, in 2001 and 2003, no one was convicted of her suspected murder.

However, her husband, a former professional rugby league player, has long been a suspect.

Chris Dawson, who played for the Newtown Jets, has consistently denied any involvement in his wife’s disappearance.