A man who was just meters away from a hit and run in Hamilton yesterday says he thought it was an accident until the driver backed up and drove into the victim a second time.



Arthur Nixon said the woman drove onto the footpath and hit the man, said to be her partner, with the car.



"We thought the first one was just an accident, that she hit the accelerator instead of the brake, but then she backed up and did it again," he said.



Nixon said the man sustained "really bad" gashes to his legs, feet, back and head.



Several people rushed to his aid, before the driver of the car "hooned off", according to Black Bull Liquor store manager Amrinder Singh.



"The customer I was serving ran outside and he just cried at her 'don't do that'," Singh said.



Dramatic CCTV footage showed a man coming into frame after being struck by the car.



The driver was seen reversing before attempting to strike the man again as he lay on the footpath outside a Melville dairy.



The woman fled the shopping centre, narrowly missing the man on the ground, but her run was short-lived as she drove the car off a 10-metre bank near the Cobham Drive bridge about midday.



A witness followed the offender's car to Cobham Drive and called police 111, keeping an eye on the vehicle until they got to the scene.



When officers arrived, the woman had driven her car over a bank, estimated to be about 10m high, into the river, , Detective Inspector Ross McKay.



"Four officers have entered the water to get the woman out.



Police flagged down a passing boat driver, Tamahere man Greg Mitchell, who took the woman to the Grantham St boat ramp where ambulance officers were waiting for her.



Mitchell, 38, said the woman was lying bloodied and face down on the shoreline when he first saw her.



Two or three police were there, comforting the woman.



Mitchell, who also had his 10-year-old son, Jett, in the boat, pulled up and used his picnic blanket to wrap her up and keep her warm.



He then transported her the short distance to awaiting emergency services.



"She's been in a car that's gone off the cliff, quite a high 20m, long way to drop . . . She's fine.



"She was soaking wet."



Police hoped to retrieve the car.



McKay said police would look into formally recognising the efforts of those involved in the woman's rescue from the river, once her car had been recovered.



He said the woman was interviewed by police yesterday but it was too early to say what, if any, charges would be laid.