A pedestrian tragedy and a multi-car crash has thrown Melbourne's Monash Freeway into peak hour chaos this evening.

All outbound lanes were closed between Warrigal and Forster Road due to a non-suspicious pedestrian death at Huntingdale Road, just after 3.30pm.

Outbound traffic has been banked up all the way to the Burnley Tunnel.

Vic Roads advised some lanes have been reopened and traffic is starting to flow again.

One lane of the Burnley Tunnel was closed to reduce congestion, but it too has been reopened.

Drivers have been urged to avoid the Monash Freeway or delay their journeys.