Police search dams near Toolern Vale in December. Credit:Jason South However, the search teams packed up around nightfall on Monday with no news of a discovery. The seachers are due to return to the area spanning from Blackhill Road to Gisborne Road, which includes grassland and farms, as well as waterways, and creeks, early on Tuesday morning. A State Emergency Services spokeswoman confirmed that police had requested about 75 volunteers resume the search around 8am. The area being searched is about 40 kilometres from Avondale Heights.

Karen Ristevski. Credit:Victoria Police In an eerie coincidence, Adrian Bayley dumped Jill Meagher's body in a shallow grave on Blackhill Road in 2012. One resident, who did not wish to be named, arrived home from work after spotting his property on the afternoon news. Police and SES search properties near Toolernvale in Melbourne's north-west as the investigation into the disappearance of missing mother Karen Ristevski continues. Credit:Jason South He said police searched nearby roads on motorbikes two months after Ms Ristevski vanished.

Afterwards, residents combed their properties for any disturbances or clues as to the whereabouts of the missing mother, terrified their quiet, rural-fringe suburb would once again make headlines for all the wrong reasons. Karen Ristevski with her husband, Borce, and daughter, Sarah. However, those searches yielded nothing of significance. Then, around October, police were back. This time, the motorbikes were traded in for a helicopter. Police and SES crews at Toolen Vale on Monday. Credit:Jason South

"They were obviously searching for something," the resident said. "They were flying quite low and looking over all the vacant land." Karen's husband, Borce, and their daughter, Sarah, 21, spoke to media not long after her disappearance last year. Credit:Penny Stephens On Monday, police said they were confident of solving the case as Ms Ristevski's family, including her 21-year-old daughter, Sarah, prepare to face their first Christmas without Karen. Mr Ristevski told police his wife had left the house at 10am to go for a walk and clear her head after they had an argument.

Police remain tight-lipped about what sparked the search. Credit:Jason South The case has been marked with bizarre theories, including that Ms Ristevski has fled overseas Police have previously searched locations across Victoria, however, their focus remains around Toolern Vale and Gisborne. Police divers search dams near Toolern Vale in the hunt for Karen Ristevski. Credit:Jason South Detective Inspector Stephen Dennis from the Missing Persons Squad said the search was the largest conducted since the investigation began.

Road blocks were in place surrounding the large search area on Monday, however the majority of activity was conducted on a property at the corner of Blackhill Road and Mount Aitken Road. "We are certainly very keen to search this area as thoroughly as we can," Detective Inspector Dennis said. He said the use of a cadaver dog did not necessarily mean police were looking for a body. "We're not ruling anything in and not ruling anything out," he said. There have been reports Ms Ristevski's phone pinged on towers on the Calder Highway and at Gisborne on the day she went missing, and data also suggested it had been turned off for two hours, however Inspector Dennis did not say if the search was related.

He also did not know if Ms Ristevski had any connection to the area. "We will search where we can," he said. Ms Ristevksi's family was co-operating with police, Inspector Dennis said, however it is unclear if there have been further interviews with her husband Borce. Mr Ristevski and his son from a previous relationship, Anthony Rickard, have been questioned by police. Despite six months without a significant lead, Inspector Dennis said police were confident of finding Ms Ristevski.

"I can highlight recent investigations where missing persons have been found some 18 or 20 months after people went missing," he said. Investigators appealed for anyone who lives in this area to consider checking their properties for any changes or any suspicious activity since the disappearance. There have been at least two searches of the Maribyrnong River near Ms Ristevski's Oakley Drive home. Ms Ristevski is described as 160 centimetres tall, slim build, shoulder length brown hair. She was last seen wearing a black jacket and jeans and it is believed she had a Coach handbag and a Coach purse with her.

Anyone who sees Ms Ristevski is urged to contact triple zero, or anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report to crimestoppersvic.com.au. - with Emily Woods