A truck crash near a NSW motorway bridge may have been caused by a base jumper throwing himself off the structure.
Emergency services were called to the Hume Motorway where it crosses the Nepean River following reports on Thursday morning that a man had climbed onto the bridge's railing and leapt off.
Initial reports suggested the man was wearing a backpack and may have been a base jumper. The bridge is a known location for the extreme sport.
Moments later, about 11am, a truck crashed into the rear of another truck in congested traffic.
"Emergency services responded to reports of a base jumper in the area moments before the crash," NSW Police said in a statement.
"A search of the area was not able to locate anyone."
The truck drivers escaped injury and the motorway has been reopened.
