The man accused of fatally shooting his neighbour in Kawerau says he pulled the trigger because he was afraid -- but was too drunk to remember why.

Robert George Oakley, a builder, is on trial in the High Court at Rotorua for the murder of Dawson Osman on August 28 last year following a day of drinking.

It was Mr Osman's birthday and he invited his neighbour, who he had never met before, to come over and drink with him and his partner's brother, Beaudine Ngaehue.

They later went to Oakley's house to drink his home brew when what started as a happy occasion, turned into a drunken shooting.

Oakley told the court yesterday that he thought he had shot Mr Osman. He said he feared Mr Osman but could not remember why.

He remembered going to his bedroom, grabbing his gun and firing a warning shot when he saw a figure coming down the hall.

"I fired a shot on the ground...I was frightened of them and I wanted to give them an opportunity to know their boundaries."

Oakley said Mr Osman kept coming at him so he shot him.

Asked by his lawyer Stephen Clews why he shot Mr Osman, he said he said: "I was frightened of him. I thought if he did have good intentions, a shot in the floor was good enough to scare him to leave.

"By now I could only assume that his intentions were bad."

Oakley said Mr Osman staggered back a couple of steps then lay down on the ground.

Oakley said he waited up to two minutes in case someone else came through the door.

He then left the house and walked into town, trying to get the attention of police. He ended up at the Shell Service Station from where police were called.

The trial is expected to finish today.