UPDATE 9.50AM: NSW Police have confirmed that the man is now in custody.
Several lanes on the Sydney Harbour Bridge remain closed this morning due to an ongoing police operation.
NSW Police are currently working to communicate with a man who climbed the bridge at about 4.30am, with emergency services waiting on ground.
As a result, two out of four northbound lanes have been closed, with speed reduced to 40km/h in all southbound lane although police are warning that lanes may open or close at short notice due to the nature of the incident.
Traffic is heavy in both directions; southbound traffic is queued back onto the M2 in North Epping while northbound traffic is queued back onto Victoria Road in Ryde and the Pacific Highway in Lindfield.
The Transport Management Centre also advise that traffic is very heavy on City West Link past Haberfield and on the Eastern Distributor, Southern Cross Drive, General Holmes Drive and the M5 East.
Motorists are still being asked to avoid the area and, if you have to cross the bridge, do so via train as buses are delayed up to 70 minutes.
We'll be keeping you updated throughout the morning on 104.9 Triple M or via the Triple M app, which you can download here.