Monash Freeway reopens after serious collision brought inbound traffic to a standstill

All lanes on Melbourne's Monash Freeway have re-opened after a serious collision brought inbound traffic to a standstill.

Emergency crews were called to the smash about 2.20pm and paramedics confirmed they treated two people at the scene, near Huntingdale Road, who were later transported to hospital.

The Transport Department has warned motorists that traffic remains heavy outbound, with delays pushing back through the Burnley Tunnel and onto the West Gate Freeway.

"There's also congestion on several roads around Chadstone, Clayton and Mt Waverley following the detours, which may take some time to ease," a department spokesperson said.