Karen Ristevski: shovel being examined

The investigation into the death of Melbourne mum Karen Ristevski includes a dirty shovel found in the garage of her home.

The Herald Sun newspaper reports soil samples taken from the shovel have been tested and one matched earth found in the Mount Macedon where her remains were found on Monday.

Victoria Police declined to comment, telling the paper "the investigation is continuing and it would be inappropriate to provide a running commentary".

The Avondale Heights mother went missing in June last year.

Her husband Borce Ristevski is yet to speak publicly since his wife's body was discovered.

His lawyer on Wednesday said while his client was a prime suspect in the suspected murder case, he maintained his innocence.

Family members have spoken about the 47-year-old's tragic end, including Ms Ristevski's stepson Anthony Rickard who urged her killer to confess.

"(It's) only a matter of time before you are spending a long time behind bars," he wrote on his Facebook page.

Ms Ristevski's brother Steve Williams has also broken his silence.

"I knew Karen wasn't coming home. I knew that from a very early stage," he told the Nine Network.

Ms Ristevski's body was found by a passerby along a dirt track off Loch Road, Mount Macedon about midday on Monday.

Police are urging anyone with information about her death to come forward.