A dog leapt over a fence to launch a vicious attack on a 71-year-old Motueka man who was getting his newspaper.

The man, who uses a walking stick, was walking down the driveway of his Motueka home about 5pm yesterday when he was attacked.

''A young female has seen the attack and gone to his aid and managed to beat the dog off with a stick. She then secured the dog to the fence,'' a police spokesman said.

A local dog ranger later impounded the the three-year-old mixed breed dog.

An investigation into the attack is underway.

The man was initially treated by a local medical centre and was then flown to Nelson Hospital by the Nelson Marlborough Rescue Helicopter.

The spokesman said he received serious bites to both his lower arms and left ankle.

Nelson Marlborough Rescue Helicopter pilot Tim Douglas-Clifford said the elderly man told him the dog, which belonged to his neighbour, attacked him as he went to get his evening paper.

He understood the man had ''nasty'' lacerations to his arms from where he had tried to fend off the dog. He had also been bitten on his lower legs.

He said the man was bandaged from his shoulders right down to his fingers.

Despite his injuries he seemed ''pretty chirpy'', Douglas-Clifford said.

The police spokesman said the man was last night in a ''stable'' condition at Nelson Hospital. A 71-year-old Motueka man is in hospital tonight after being seriously injured in a dog attack.

The man, who suffered serious limb injuries, was flown to Nelson Hospital by the Nelson Marlborough Rescue Helicopter crew about 6pm.

He was treated on board the helicopter by a St John paramedic after being cared for by St John ambulance staff and police at the scene of the attack.

- © Fairfax NZ News