The 49-year-old walked out of her home in Melbourne's north-west at around 10am after an argument with her husband over money.
The last thing Karen reportedly told her husband, Borse Ristevski, was "I’m going to go and clear my head."
Though Mr Ristevski denies having any involvement in the disappearance of his wife, both his and Karen's phones “pinged” off transmission towers on the Calder Freeway on the day of her disappearance and Mr Ristevski's phone was then switched off for two hours.
Police have named him the primary suspect in their case.
Now a man, who has chosen to remain anonymous, has revealed chilling comments Borse Ristevski said to him in the months leading up to his wife's murder.
In a 7 News exclusive, a man claims he first met Mr Ristevksi through a mutual friend in South East Asia in March last year.
“The first time I met him… he sent shivers down my spine,” the man said.
“I asked him a few questions… if he was married and that, he didn’t reply back to me. I found that a bit weird.”
But it was another comment Mr Ristevski allegedly made that prompted the man go to police when he heard news of Karen Ristevski’s death.
“This is a good place to get rid of somebody,” Mr Ristevski allegedly said while the pair were catching up over a few drinks.
“It’s not like something you say to someone you’ve just met. There was something eating me up inside saying I should report it to police.”
Police have confirmed they are investigating the man’s claims.
This article first published on Marie Claire.