31-year-old Mohamud Hussein, was found injured at 11:30pm in Melbourne on Wednesday night.
Police performed first aid until paramedics arrived but he later died at the scene.
Detective Inspector Mick Hughes told ABC News that he was "brutally assaulted" after parking his car nearby.
"It may be just a spontaneous attack. [Someone has] seen this gentleman get out of his taxi, probably at the end of his shift, and working on the assumption he has large amounts of cash," he said.
"The unfortunate thing is these days most taxi drivers don't. A lot of the transactions are done on credit card, so he had very little cash on him.
"[His] dad shares the cab with him, it's actually dad's cab. So just a tragedy for the family.
"He was walking home. Like most people, he keeps to a pretty strict schedule, and dad's started looking for him when he hadn't got home."
Detective Inspector Hughes said his wallet and phone were found next to his body.
He said Mr Hussein received upper body wounds but it appeared no firearms were involved. No weapon was found either.
Detective Inspector Hughes said he was "confident" a passenger was not involved in the death.
The incident occurred near the Fitzroy Police Station, in inner Melbourne, on the corner of Condell and Napier streets at 11:30pm on Wednesday night, police said.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au
