Homicide Squad detectives are investigating the circumstances surrounding the death of a male in Werribee this evening.
Emergency services were called to an address on Ballan Road about 5.50pm to reports of an injured male.
A 17-year-old Wyndham Vale boy was taken to hospital with life-threatening injuries and later died.
A 15-year-old Wyndham Vale boy has been arrested and is assisting police with their enquiries.
Anyone who witnessed the incident or with information is urged to call Crime Stoppers on 1800 333 000 or visit www.crimestoppersvic.com.au