Vancouver police continue to excavate the basement of an East Vancouver townhouse after a Maple Ridge, B.C., man came forward to say he watched his father kill his mother there more than 30 years ago.

Robert Sturcz, 38, told CBC News he was five when his 350-pound violent, alcoholic father Aladar Sturcz broke his mother's neck in the basement of the Rupert Street townhouse, and later buried her under the concrete floor.

Sturcz said after his father first tried to kill his mother, Katherine Mary Brown, he called him down to the basement and told him to make sure she didn't move until he got back.

"She started moving and I said, 'Don't move … don't move!' And then Dad came down and saw she was moving and told me to go upstairs. Later I came down and she's laid out … broken neck," he told CBC News at his Maple Ridge home on Wednesday.

Sturcz said his father was a violent alcoholic so he did what he was told and didn't talk about it either.

A police truck is parked at the entrance of the home on 4842 Rupert St. in East Vancouver on Wednesday. (Aarti Pole/CBC)

"I saw it. [I] was there. He made me sleep down there while she was dead down there for a couple of nights," he said.

"I remember being five years old pulling at her hair, poking her with a needle trying to get her to wake up," he said.

He said his mother's body lay there for two days until his father buried her body in the basement of the suite.

"My sick dad a couple of days later dug up the ground and chucked her in there, poured lime on her," said Sturcz.

"He gets me to help him later very quietly … as quietly as he could break the floor and dug the floor up with the help of one other grey-haired fella which I can't remember what he looked like," he said.

Forensic excavation begins

Neighbours say the residents of the house were moved out last month and police arrived this week with heavy equipment, including jackhammers, and began work in the basement.

Vancouver police said they are working with forensic and archaeological specialists on the excavation and they expect to be at the site for at least a week.

They have confirmed they are looking for a body of a woman who went missing in 1977, but they have yet to release her identity. But Sturcz said he knows what police are going to find.

"They're going to find a purse. They're going to find a status card. They're going to find a statement written by me in crayon my dad made me write that it's my fault," he said.

Stucz said his mother was a First Nations woman from the Lake Babine Nation near Burns Lake who suffered from low self-esteem at the hands of her abusive husband.

He said his father was a concentration camp survivor from Hungary who taught him how to kill people at the age of six.

"I knew he was kind of whacked in the head… so I was afraid to tell the police what happened back then, because I was afraid he was going to hurt my family," he said.

Turned to drugs to forget

Sturcz's father Aladar died in 1987 and was buried at Mountain View cemetery. Sturcz said he turned to drugs at the age of 17 to try to forget his mother's death, and only managed to get off them two years ago.

"When I first started remembering about it when I was 17, I needed to do cocaine to forget about it. So I've been clean off the cocaine now for two years," he said.

Eventually Sturcz told his story to former Downtown Eastside beat cop Dave Dickson, who said he's known Sturcz since he was 12 and believed the story.

"With Robert I believed him right from the get-go. It was just too detailed to be dreaming it or hallucinating it," said Dickson on Wednesday.

"He trusted me enough to come forward with it. And the first thing he said was, 'You don't think I'm crazy?' and I said, 'Of course not,'" said Dickson.

Sturcz said he is hoping when everything is done, he'll finally be able to give his mother a proper burial.

"It'll make me happier that my mom isn't haunting the house no more. I believe in ghosts," he said.

Project residents remember father

Tammy Western said she grew up near the townhouse in the low-income housing project and remembers the Sturcz family well, and the tough nature of the father still stands out for her.

"He was a home father, which we felt was rare. Yeah, we didn't mess with the dad, we knew he would probably kick our butt, you know, he wouldn't put up with our stuff. He bossed. He ruled the roost there," she said.

Western said she remembers asking where the mother was, and being told only that she was gone, and she learned not to ask anymore.