A 24-year-old man, Samson Byshomi, was critically injured in the Lake Avenue collision about 10.05pm Saturday. He was knocked unconscious and required life support on the roadside. He was later flown to St George Hospital for surgery to head and leg injuries.

After collecting CCTV footage from nearby shops and tracing the car's rental history, Wollongong police caught up with Pakistani national Ahmer Nasir at his West Wollongong sharehouse Sunday afternoon.

They found Nasir's badly damaged hire car in the driveway, with dents to the passenger-side front end and a rear-vision mirror left dangling by some cables.

In an interview with police, the UOW student admitted he was driving the car at the time of the collision, but said he hadn't seen a pedestrian. He said he thought he had hit a bird and could not find a place to stop and check.

He claimed he drove home before checking the car and that when he saw the damage, he and his flat mate drove back to where he thought the crash had occurred, but could not find the location.

The 21-year-old spent a night in the cells before appearing at Wollongong Local Court Monday, charged with dangerous driving occasioning grievous bodily harm, fail to stop and assist after vehicle impact causing grievous bodily harm, and negligent driving.

Police prosecutor Kylie Talty opposed bail, citing the seriousness of the charges and concerns that Nasir posed a flight risk.

"He told police he thought he'd collided with a bird and that's why he didn't stop," Sgt Talty said. "He's collided with a pedestrian who's gone over the bonnet of the vehicle, up over the A frame and collided heavily with the road surface. He's then failed to stop and render assistance."

The court heard Nasir had surrendered his passport to police.

Magistrate Robert Walker agreed to grant bail, on condition that Nasir report daily to Wollongong Police Station, not enter any international point of departure, abstain from alcohol and drugs and not contact the victim.

Police have seized the damaged car - a white Suzuki sedan - for forensic testing.

The court heard the injured man had been crossing the road from the eastern side to the western side when he stepped into the path of the sedan.

The car collided with his legs and he landed heavily on the road.

Footage of the crash, captured on CCTV cameras from a nearby business, show the injured man's friends rushing to his aid in the moments afterwards.

The matter returns to court October 13.