According to police, the motorcycle was moving along the on-ramp to the Princes Freeway at Kororoit Creek Road in Altona around 10.30am when it lost control and collided with a barrier.

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

The outbound entry to the Princes Freeway from Kororoit Creek Road is closed as a result of the collision.

Drivers are advised to reroute via Maidstone Street, Queen Street, Central Avenue through Altona, or use Fitzgerald Road, Boundary Road, and the M80 Ring Road to access the Princes Freeway.

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

An investigation into the circumstances surrounding the crash is ongoing.

Drivers are urged to avoid the outbound entry from Kororoit Creek Road and expect delays as police conduct collision investigations.