"If the woman hadn't come to the door ... I probably wouldn't have gone into the house.
"She was fumbling for the door handle, and I was yelling at her. Then I saw her take a couple of steps back and she just disappeared in the thick black smoke. Then I heard a large thump and I realised that she was on the ground."
Mr Oldham said he looked around for help but nobody else was there.
"I started kicking the grill door but there was no way the door was breaking."
Mr Oldham smashed a window and black smoke came billowing out.
"I think that is when the adrenalin kicked in and I just wrenched that window and managed to pull it right off its hinges, pulled my little LED torch out and took a breathe and went inside through that gap."
Mr Oldham was faced with trying to find the woman in choking "thick, black, acrid smoke".
His torch light wouldn't penetrate the black smoke, which was so thick he had to go back outside to get another breath, and made several attempts to re-enter the house.
"I do remember standing there thinking 'I can't do it, I can't do it'," he said.
But decided he had no choice.
"That was somebody's grandma in there and I just new it was up to me," he said.
Mr Oldham found the woman, grabbed her heels and pulled her towards the window but needed help from fellow officer, Constable Shane McCarthy.
Mr Oldham said the rescue was probably all over in a couple minutes but it seemed longer.
"I didn't really think about my own safety. It wasn't until after the one of fire marshalls spoke to me and said that if I hadn't done that this woman would have died ... I sort of got a little bit emotional then, because I thought I really had saved this woman's life."
Mr Oldham said he felt humbled by all the attention.
"I've been shot at, I've been kidnapped and a lot of those sort of things, but this in particular is really probably going to stick in mind more than anything else, because I've saved a life, and that is probably pretty special," he said.
One of the victim's daughters said that she, her mother and other family members wanted to thank all the emergency services and police staff involved, especially Mr Oldham and Mr McCarthy.
"They've been absolutely amazing.," she said.