Major Collision Investigation Unit detectives have arrested a man in relation to a fatal collision in Powelltown earlier this month.
It is alleged two motorcyclists were travelling at high speeds east on Yarra Junction-Noojee Road on 8 January.
One of the riders, a 23-year-old Northcote man, was involved in a head-on collision with an unrelated motorcyclist, a 77-year-old Croydon man, who was travelling west about 1.30pm.
The 77-year-old rider was taken to hospital with life-threatening injuries where he remains in a stable condition.
The 23-year-old rider died at the scene.
A 22-year-old Mooroolbark man, who was riding behind the deceased at the time of the collision, was not injured.
Police executed a search warrant in Mooroolbark this morning and arrested the 22-year-old.
He was taken into custody and will be interviewed by detectives.
Police are continuing to appeal for anyone who witnessed the crash, or may have dashcam vision from Yarra Junction-Noojee Road between 1.15pm and 1.30pm on 8 January to contact Crime Stoppers on 1800 333 000 or www.crimestoppersvic.com.au