Mr Tapp was one of the first on the scene.
"My wife and I had been at the Elgin shops getting some takeaway food. We were driving away when I smelled burning," he said.
"Then I saw the smoke coming from a nearby flat, and I realised that it was my cousin's place," he said.
He ran to the front door, calling out his cousin's name. When there was no reply he decided to break in.
"I tried to kick in the front door but my boot slipped on the wood. I had another go and this time smashed through the glass panelling in the door."
He then managed to get the door open.
"It was all black with smoke inside the flat and the flames were fully erupted.
"I saw what I thought was a mattress on the floor in front me, just inside the flat and pushed at it. "I heard a moan and realised I was looking at my cousin on the floor."
Mr Tapp lifted him by the upper body to try to pick him up.
"His back was on fire and I got my fingers burned trying to lift him, so I grabbed him by the ankles and dragged him to the doorway."
Mr Tapp could hear the windows in the flat breaking.
"I called for someone to help me but no one came, so I kept dragging him through the door on to the porch, and was able to get him on to the grass verge outside."
At that point help arrived.
"A young guy came running up and together we managed to drag him further away from the flat."
Other people arrived and they administered first aid until emergency services arrived.
The man, who lived alone in the flat, was initially taken to Gisborne Hospital.
"He had suffered critical burns to a large area of his torso and legs," a St John spokeswoman said.
He was admitted to the hospital's intensive care unit, then flown to Middlemore Hospital yesterday for more specialist care.
"He is in a serious condition in our ICU," a Middlemore spokeswoman said this morning.
The cause of the fire has been investigated.
"We have done a scene examination and identified where we believe the fire started," said Detective Sergeant Kevin Ford.
"We will speak to the man when he is well enough and we are not looking to speak to anyone else about the incident."
Police described Mr Tapp's actions as "very brave". He was treated at the scene for the burns to his fingers.
Mr Tapp had no doubt that if he had not arrived when he did, his cousin would have died.
"I didn't think about the dangers - I just knew I had to help my cousin."
