Despite the police not having released any information, a friend who has been acting as a spokesperson for Ms Ristevski’s stepson Anthony Rickard is said to have spilled the information to news.com.au.
The friend claims that he had evidence a mannequin was also placed in the front passenger side of the car as it was driven to Ms Ristevski's resting place in Mt Macedon - perhaps acting as a decoy.
Detective Inspector Tim Day, who is leading the investigation, refused to confirm or deny the friends claims or confirm if he or Mr Rickard had been interviewed by investigators about their claims, reports news.com.au.
However neither the friend, nor Mr Rickard have been named as suspects in the case.
There are further reports that the friend was called to a Melbourne police station late on Friday morning and confronted over allegedly spreading misinformation about the case.
47-year-old Karen went missing on June 29, 2016, and was last seen at her Avondale Heights home by her husband, Borce.
Her body was found in bushland in Mt Macedon Regional Park on February 20.