A Melbourne heart surgeon has died almost a month after he was punched outside a hospital for telling someone to stop smoking.
Police on Wednesday confirmed Box Hill Hospital surgeon Patrick Pritzwald-Stegmann died overnight.
Four weeks ago Dr Pritzwald-Stegmann was hit in full view of CCTV and rushed to the state's premier trauma centre at The Alfred hospital.
Mill Park man Joseph Esmaili , 22, has been charged over the attack and faced court earlier this month.
The investigation will remain in the control of the local crime investigation unit but will be overseen by the homicide squad.
"Investigators will now await the results of a post-mortem before reviewing charges," police spokeswoman Natalie Savino said in a statement.