A rider has died after the motorbike lost control in Melbourne’s west.

The bike was travelling along the Kororoit Creek Rd on-ramp of the Princes Fwy in Altona when it crashed into a barrier just after 10.30am on Thursday.

The rider, who is yet to be formally identified, died at the scene.

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“An investigation into the circumstances surrounding the crash is ongoing,” police said.

The outbound entry from Kororoit Creek Rd to the Princes Fwy is closed, resulting in delays.

Drivers who want to get onto the freeway should detour using Maidstone St, Queen St, Central Ave through Altona, or take Fitzgerald Rd, Boundary Rd and M80 Ring Rd onto the Princes Fwy.

All lanes remain open on the freeway in both directions near the incident.

“Drivers planning travel in the area over the next few hours should plan to avoid the outbound entry from Kororoit Creek Road as emergency services conduct investigations,” the department of transport said.

Anyone who witnessed the incident or has any dashcam footage is urged to contact Crime Stoppers.