An Ōrewa constable feared the worst when a radio call cut through the rain on a miserable Sunday to tell him a man and his dog had fallen down a steep cliff face.

When Constable Roger Dustow arrived at the beach on May 12, he could not hear anyone on the cliff face.

A witness told him the man's mastiff cross had broken its lead running towards the cliff. The man tried to grab the dog but they went over and rolled down the cliff.

As Dustow waded into the freezing, waist-deep water at the bottom of the cliff, he called out to the man, listening for an answer.

"We had search and rescue on standby," Dustow said.

Incredibly, the man, Doug Wheeler, in his 30s, had survived along with his dog, and was clinging to a tree in the pouring rain. It was a 25-metre drop and Wheeler had fallen about 20 metres, Dustow said.

Fire and Emergency New Zealand were fantastic, Dustow said, and managed to extract the pair by harness from the top, pulling the dog up first.

It only took about 30 minutes but probably felt a lot longer to Wheeler because he would have been hanging on for dear life, Dustow said.

"It's a bit of a miracle that he survived to be honest, because people that go over there don't normally make it.

"I was fearing the worst when the job came in."

When Wheeler was pulled to the top of the cliff, he only had minor facial injuries.

"He was one lucky lad."