Motorcyclist serious after Sydney M7 crash

A motorcyclist is in a serious condition after an accident on western Sydney's M7 motorway, which has closed southbound lanes while officers examine the scene.

The accident, which occurred just after 11am on Saturday, is near the Jedda Road overpass at Prestons.

The rider was treated at the scene by paramedics and taken to Liverpool Hospital.

All southbound lanes are blocked near the accident and motorists are being diverted off the M7 via Bernera Road, the Transport Management Centre said.