UPDATED 4.48PM: Traffic is still down to one lane on the Tauranga Harbour Bridge.
Long delays can be expected if travelling towards Tauranga along Hewletts Rd.
EARLIER: A lane of Tauranga Harbour Bridge has been closed following an oil leak from a truck.
Police and firefighters are at the scene, near the first off ramp to Tauranga for south-bound traffic.
It is understood sand has been called for to help clean up the mess.
Traffic headed to Tauranga has been whittled to one lane until the oil is cleaned up.
Acting Senior Sergeant Iain Chapman said the damage to the truck was caused by a large metal disc which was lying on the road.
"This piece of metal has been flicked up by another car and under the truck , causing damage to the truck oil sump."
He said it was not yet clear when the lane would be reopened.
It is understood the spill was spread about 500 metres.