Stephen Williams, in a statement, said it had been a surprisingly emotional day.

"One in which I have patiently waited to arrive," he said.

"It is in no way a celebration, but just another stage in bringing my beautiful sister Karen the justice she so deserves.

"Again, a huge thank you the members of the Missing Persons Squad. Also to Emily, Lachlan, my cousins and work colleagues who have been very supportive these long 18 months."

Borce Ristevski was charged with the murder of his wife early on Wednesday morning, almost 18 months after she disappeared from their home in Avondale Heights.

Mr Ristevski's lawyer Rob Stary told a court hearing on Wednesday his client would be pleading not guilty.

"This man doesn't have any history and we want the matter expedited," Mr Stary told the court.

Mr Ristevski was remanded in custody to return to court on April 18. He nodded to the magistrate as he was led out of the dock and back into custody.

Ms Ristevski went missing from her million-dollar Oakley Drive home in Avondale Heights - a riverside suburb in Melbourne's north-west - where she lived with her husband and their 21-year-old daughter Sarah on the morning of June 29, 2016.

The disappearance of the fashion boutique owner captivated Melbourne as police mounted an exhaustive search for any sign of her.

Her friend, actor Samuel Johnson, pleaded for information about her whereabouts to a national television audience via The Project on Channel Ten.

The body of the 47-year-old mother was found eight months later, 50 kilometres from her home, concealed under a log in the Mount Macedon Regional Park.

The case of Ms Ristevski's death has been punctuated with rumours and theories since the 47-year-old mother disappeared.

Mr Ristevski's brother Vasko claimed his sister-in-law fled overseas using a fake passport, while Mr Ristevski's son from a previous relationship, Anthony Rickard, told various media outlets there was a conflict within the family and his stepmother had planned to leave his father.

Mr Rickard declined to comment when contacted by Fairfax Media on Wednesday.

In June, almost a year after she went missing, police released CCTV footage of a black Mercedes-Benz SLK coupe travelling towards Mount Macedon on the morning of Ms Ristevski's disappearance.

Mr Ristevski reportedly told detectives he had driven his wife's 2004 Mercedes-Benz coupe on the day she disappeared to test a faulty fuel gauge.

He said the car hit a bump in the road and the problem fixed itself, so he turned around and went home.

Come June, missing persons detectives had used a painstaking process of elimination to identify fewer than 20 owners of coupes to speak to about what they were doing on the day Ms Ristevski disappeared to make sure the car caught on CCTV belonged to the missing mother.

The couple had also been facing financial problems before her disappearance.

Caveats had been placed on their $1.1 million family home by lenders and Ms Ristevski's fashion boutique Bella Bleu, which had two stores in Taylor's Lakes and Broadmeadows, had closed.

Mr Ristevski was a pallbearer at his wife's funeral in March.