The alleged final moments in the tragic life of Danny Wallis have been told for the first time to a jury.

His cousin, Travis Smith – who denies murder – has claimed the argument which led to the killing was over a light switch.

The 24-year-old, of no fixed address, told how the two had argued at Danny’s flat in Gravesham Court in Gravesend last May.

It ended with 29-year-old Danny's body being discovered in a bath of water. The prosecution has claimed he was throttled to death.

But Smith alleged he was attacked with a knife and punched his cousin in self-defence, before grabbing him around the neck.

“We both fell backwards. I had never seen Danny with a knife before. At first I didn’t think anything was going to happen but then he lifted it up and I thought he was going to stab me..that’s why I hit him.

“His hand then swung back to the side of my head and I moved my head..and the next minute Danny just went limp.”

His barrister Jonathan Mann QC asked earlier: “Have you ever wanted to really hurt Danny?”

Smith replied: “No, of course not.”

The roofer claimed that his cousin had been smoking crack cocaine with other friends at the flat when he arrived after drinking all day.

When three other people had left, Smith and his cousin were alone and Danny began pacing up and down the hallway.

“I said: ’What’s the matter? Come sit down and have a beer and that. He came and sat down for a minute. I said: “Why are you doing crack?” He didn’t say anything.”

Smith claimed that Danny then got up, went to a fuse box and turned off the trip switch.

“I said: ’Why have you turned the lights off?’ He didn’t say anything, so I turned the switch on again. He did it again and I turned it on again. He turned it off again.

“This time I held my hand on the switch. I can’t remember what I said to Danny but he grabbed my arm and bit my hand. Then I slapped Danny in the face.

“I said: ‘You are an idiot. I am going, “then I went into the kitchen to get my bag and my beer from the fridge. I walked back in and he tried grabbing me. I just wanted to get away.”

Smith told the body-in-the-bath murder jury at Canterbury Crown Court how he then went to the bathroom to wash his hands and noticed the bath was half full of water.

“I heard Danny in the kitchen saying: ’I’ll get you out’ and I said: ’I’m going anyway, Danny.

“He was next to me and he had a knife, which I had seen earlier in a shoebox on a table which was used to cut cannabis.”

Smith asked: “What are you doing, Danny” before walking towards him thinking he would step back.

“But he just lifted up the knife so I hit Danny. I hit him in the face because he had a knife in my face.

“Then I went round the back of him and put my arm around his neck. I can’t really tell you why I did it.”

He claimed the two stumbled into the bedroom – still with Smith’s arm around his cousin’s neck.

“I am really not sure if he dropped the knife. I couldn’t see Danny’s hands.

“He was struggling...we were both struggling. I fell backwards and Danny landed on top of me. My arm was still around his neck. I kept shouting: ‘Stop, what are you doing?’ He didn’t say anything to me.”

It was then, Smith claimed, that his cousin’s body went limp.

The trial continues