NSW Ambulance has confirmed it’s responding to reports a man has base jumped off a Hume Highway bridge, south-west of Sydney.

The incident happened at the same time as a two-truck crash on the bridge at Douglas Park, closing all lanes of the Hume Highway southbound.

It’s unclear if the incidents are related at all but paramedics have confirmed nobody was hurt in the truck crash.

Emergency services are searching for the person who reportedly jumped from the bridge and is believed to have landed safely.

Listener Lenny phoned The Ray Hadley Morning Show in shock after witnessing the incident.

“I was heading northbound, there was another truck in front of me.

“All of a sudden this bloke just climbed up onto the rail and jumped.

“I didn’t know he was a base jumper but I thought geeze that’s all I need to see. All these horrible thoughts went through my mind.

“When the police rang me back they said ‘it’s just the usual base jumpers we get out here’.”

Click PLAY below to hear Lenny’s distressed call

DOUGLAS PARK: Southbound traffic on Hume Mwy is using breakdown lane to travel past 2-truck crash on Nepean River Bridge, with lanes closed. Expect lengthy delays as traffic is queued around 6km. pic.twitter.com/l2PctlbpAN

— Live Traffic Sydney (@LiveTrafficSyd) April 19, 2018

Image: Google Maps