Seven vehicles and 29 people were involved in a collision on EastLink.
Greater Dandenong CIU Senior Constable Matthew Moore said six people were taken to the Dandenong and Monash hospitals for observation with non-life threatening injuries following the Saturday 27 January crash.
He said the pile-up occurred between the Greens and Thompsons roads freeway exits in Bangholme about 11.05am.
Sen Const Moore said the cause was unknown and urged any witnesses to call Crime Stoppers on 1800 333 000 or contact Casey Highway Patrol.
