Police believe they are homing in on the killer of Victorian mother Karen Ristevski as new details surface about her car, along with an iPad featuring a series of suspicious Google searches and new footage of her brother-in-law.

In the latest twist in the ongoing case, Channel Nine’s A Current Affair program — filming in the Macedon Regional Park last week — revealed they stumbled upon Ms Ristevski’s brother-in-law Vasko Ristevski lurking near the site her body was discovered.

Mother-of-one Ms Ristevski, 47, was reported missing on June 30 last year after her husband Borce Ristevski, 52, last saw her at their Avondale Heights home in Melbourne’s north-western suburbs.

Her decomposed body was found by bushwalkers wedged between two large fallen trees in expansive pine plantations at Mount Macedon in Melbourne’s northwest on February 20 this year.

Ms Ristevski, whose Bella Bleu clothing boutique in Broadmeadows closed down early last year, did not use her mobile phone or bank accounts or make contact with friends or family in the months after she went missing.

New CCTV footage released on Friday captured what police believe is Ms Ristevski’s black Mercedes-Benz SLK coupe following several other cars over train tracks in Diggers Rest just after 11am on June 29, 2016.

Victoria Police’s Missing Persons Squad Detective Inspector Tim Day told reporters they wanted to eliminate any possibility the two-seater Mercedes belonged to anyone else, with fewer than 20 vehicle owners yet to be contacted.

Detective Inspector Day said he believed only one person was in the Mercedes at the time the CCTV was captured.

Police believe the Mercedes-Benz was driven through Diggers Rest to Gisborne, then past Mount Macedon Golf Club towards Macedon Regional Park, where her body was found.

Husband a ‘suspect’

Detective Inspector Day told the press conference her husband was a suspect.

“I’ll leave others to judge as to what makes him a suspect, but all I will say at this stage is yes, he remains a suspect into the death of Karen,” he said.

“We suspect that may be her car, we’ve still got a little bit of work to do to eliminate other cars, certainly in the state of Victoria, from being that car,” Detective Inspector Day said.

Karen (centre) and Borce Ristevski with their daughter Sarah. Photo: Supplied.

“Ultimately the person who’s done this has a story to tell and they generally only get one chance to tell it, I’d encourage them if they’re so inclined to tell it now,” he said.

Mr Ristevski told police he took his wife’s car out for a drive on June 29 but did a U-turn and returned home. Earlier this year his lawyer told Fairfax his client was a “prime suspect” in the case.

Police have not charged Borce Ristevski with any offences related to Mrs Ristevski’s disappearance and he maintains his innocence.

Shock TV vision

On Saturday, it was revealed A Current Affair reporter Martin King was filming in the isolated Mt Macedon area where Ms Ristevski was found when his crew captured Vasko Ristevski emerging from the forest.

Mr King approached Mr Ristevski’s late model dark 4WD Nissan Patrol and asked: “Can you tell me what you’re doing here, Vasko?”.  He shook his head and refused to answer questions before getting into the vehicle and driving off.

Vasko Ristevski is filmed by a Channel Nine crew leaving the Mt Macedon forest. Source: Channel Nine

iPad evidence

On Saturday Melbourne’s Herald Sun revealed an iPad containing Google searches was seized from the Avondale Heights home of Ms Ristevski and her husband.

According to the Herald Sun report, the iPad’s history included Google searches on how police can detect traces of blood, how mobile phone data can be deleted and how police might track phones.