Officers had initially charged 22-year-old Thomas Camus with causing grievous bodily harm following the incident which took place near a nightclub in the remote Western Australian tourist town of Broome.
"The charge has been upgraded to murder," a spokesman for Western Australia police said Tuesday.
The charge relates to the death of Kristopher Dixon, 32, at about 2:00 am on Christmas morning after allegedly being involved in several altercations.
When charging Camus with grievous bodily harm on December 27, police had warned that they might upgrade the charge pending the result of the post-mortem examination.
"Police will allege that the victim was involved in numerous altercations with different people before the alleged offender confronted him, stabbing him to the chest," they said in a statement at the time.
The Frenchman was Tuesday remanded in custody until January 18, a courthouse official told AFP.
The Australian Broadcasting Corporation reported that Camus appeared in Broome Magistrates Court via video link and did not react when told the charge against him had been upgraded to murder.
Police are still calling for witnesses to the incident to come forward.
"We have spoken to lots of people that were there on the night but if anyone has information and they haven't been spoken to, we certainly urge them to contact us," acting Detective Senior Sergeant Tony Wilson told the ABC.
Wilson said the timing of the death was distressing.
"Any time someone dies in a violent offence or violent incident it's very serious," he said.
"It's always tragic for someone to lose a loved one but especially on Christmas morning, it's tragic for this family."
Police have already charged three other men -- aged 25, 29 and 32 -- with assaulting the victim shortly before his murder but the trio are not accused of being responsible for his death.
Authorities will reportedly allege the three men punched and kicked Dixon during a separate fight when the case comes to Broome Magistrates Court later this month.