A motorist couldn't believe his eyes tonight as he drove past a person attempting to ride a Lime e-scooter over the Auckland Harbour Bridge.

The rider was heading northbound and was shielded by a ute behind him with its hazard lights on, forcing traffic behind them down to a slow trundle.

Meanwhile, police received numerous reports about the scooter rider but were unable to find him.

The motorist, who was bound for Northcote Point, said traffic in the two left hand lanes prior to the bridge were slow moving while the other lanes were free-flowing.

"I thought, 'what is going on here'," he told the Herald.

"I came up a little closer and saw the ute had his hazard lights on and thought he'd broken down but no, he was protecting [the rider].

The ute was shielding the scooter rider. Photo / Supplied

"He was slowing traffic down behind him and protecting the guy going up the bridge, only for that guy there could have been an accident, very easily."

The motorist didn't report the incident to police but said as he drove away he noticed flashing lights from a police car behind him.

A police spokeswoman confirmed to the Herald they received a number of reports relating to a person riding a scooter over the bridge.

"We have undertaken an extensive area search and spoken to people in the area the person was last seen but are yet to locate anybody," she said.

In December, a man was caught green-handed by witnesses as he headed north over the bridge.

A police spokeswoman said officers rushed to the scene and moved both man and scooter off the bridge to a safe area.

The spokeswoman confirmed it was illegal to ride electric scooters on the Harbour Bridge.