He believed he was under threat when he fired three shots at a senior Reserve Bank official, killing him in the driveway of his Pretoria home five years ago, a former police inspector told the High Court in Pretoria on Tuesday.

Former inspector Daniel Pienaar testified in a civil trial in which the wife and son of the man he killed, Reserve Bank official Eric Gugger, is suing him and the Minister of Police for R2.5-million in damages.

Mrs Rosemarie Gugger is suing for her loss of support, following the death of her husband in August 2004, while her son, Bjorn (29) is suing the police for unlawfully arresting and assaulting him.

Pienaar testified that he and two of his colleagues were on their way to the Lyttelton police station with two suspects when Gugger Jr raced past them, almost causing an accident.

When they stopped next to Gugger Jr, they motioned for him to stop and one of his colleagues showed the man his appointment certificate.

Gugger Jr nodded that he understood, but then drove onto the gravel past them and started racing through the streets, ignoring numerous red traffic lights, making u-turns and nearly running down an attendant when he raced through a petrol station.

They followed Gugger Jr to a house in Pierre van Ryneveld, where his two colleagues jumped out and followed him in before the gate could close.

"I was on the police radio and was standing at the car door with the microphone still in my hand. The next moment someone grabbed me from behind... He pushed what I presumed was a firearm into my neck.

"I put my hands up so that the person would not shoot me. The person said: 'if you move, I'll kill you. Who are you?'

"I turned around suddenly and saw that he had a cocked firearm in his hand. I explained to him that I was a police inspector. He did not react.

"...I decided to get away. I passed under the person's arm and pushed his shoulder.

"He was half upright and turned in my direction with the firearm.

"I realised the person was going to shoot me... I drew my firearm and immediately started firing.