A 17 year-old boy has been arrested after a stolen van crashed into the back of a truck while trying to flee police in Victoria's west, killing a female passenger.
The crash occurred on the Western Freeway at Ballan just at about 2:30pm on Tuesday.
Police had tried to pull the van over but it is alleged the van did not stop.
Two people then escaped from the van and fled, one was later arrested at Wendouree West.
The investigation will be overseen by the Professional Standards Command.