An Alberta man accused of abusing his three daughters is facing 23 sex charges, including incest and procurement of a child for sex, and 17 weapon charges.

The 41-year-old man, from a small town west of Edmonton, was arrested in November, the internet child exploitation unit of the Alberta Law Enforcement Response Teams (ALERT) said Friday.

This family's nightmare continues. - RCMP acting Insp. Pamela Robinson

"The arrest may have stopped the abuse, but this family's nightmare continues," acting Insp. Pamela Robinson of the RCMP said at a news conference Friday.

"These are three girls that faced regular and prolonged abuse at the hands of their father; acts of evil that were incomprehensible to our most hardened investigators."

The man's name is not being released to protect the identities of the girls.

Edmonton police Staff Sgt. Stephen Camp said details of the case were "nauseating" for investigators.

Crimes were 'monstrous'

"​It makes the investigative committee feel quite sick here that for so many years of their childhood they were psychologically imprisoned by their father for sick and sexual purposes," Camp said.

"These crimes were quite monstrous to the family and to society at large."

The man is alleged to have abused his daughters many times over the past six years, while the girls were all under the age of 18.

One of the daughters was allegedly procured for sex with strangers more than once, with the father recording the encounters on video, police said.

The girls are receiving help from a variety of support services.

ALERT is working with the Canadian Centre for Child Protection in using a cutting-edge program called Project Arachnid to remove data and pictures involving the girls online, Camp said.

The charges against the man include human trafficking, procuring a child for sexual activity, arranging a sexual offence against a child, sexual assault with a weapon, making child pornography and distributing child pornography.

Property like a 'compound'

The girls were isolated from contact with the outside world, Camp said. The family home-schooled and the rural property was like a "compound," police said.

Police seized about 40 restricted handguns and rifles, along with a machine-gun and a dozen prohibited devices, when the property was searched in November.

The 17 firearm charges include careless storage, unauthorized possession, and possession of prohibited devices.

Two other children, both boys, lived in the home, as did the children's mother, Camp said. He said the mother was also a victim in the case, and that she didn't know what the father was doing with the girls.

The investigation involving the RCMP, Edmonton Police Service, Child and Family Services, Zebra Child Protection Centre, and the Canadian Centre for Child Protection, began in mid-October.

Investigation complex

The case, the largest to date for the internet child exploitation unit, was complicated with many layers, Camp said.

The family came to the attention of police when a witness came forward with "fourth-hand information and we backtracked that information to a primary witness ... a close associate to the family," Camp said.

The information the witness gave police was surreal, he said, calling the person extremely courageous and credible.

Any attempt to arrest the man, who had no criminal record at the time, was a "huge risk" with the number of firearms in the residence, Camp said.

However, preparation and days of surveillance on the home ended with an arrest without resistance, he said.

Christy Dzikowicz, director of child safety and family advocacy at the Canadian Centre for Child Protection, called the case "unbelievable."

But she stressed that no amount of trauma is insurmountable.

"The fact that they've been rescued and the abuse has come to light and that different support systems can be put in place is enormous," Dzikowicz said Friday. "There are some great services and supports that will come into play to help these girls heal.

"Dealing with any form of trauma, it's going to be a long road," she added. "These are the kinds of traumas that stay with you, unquestionably, probably for the rest of their lives. But that does not mean that they can't live a fulfilling life."

'Dark cloud'

Camp said in his 26 years as a police officer he has never seen such a file. It's one he will never forget, he said.

The man has remained in custody at the Edmonton Remand Centre since his arrest last year while police investigated further.

The father's arrest was like a "dark cloud" being lifted for the girls, Camp said.

"It is as if they had been emancipated from the grip or the prison of the father," he said.

"No child should have to endure what these three girls have survived."

The accused is scheduled to appear Monday in provincial court in Evansburg, 100 kilometres west of Edmonton.

ALERT teams, funded by the Alberta government, draw members from the sheriffs' department, the RCMP and police forces from across the province. They are dedicated to investigating serious crimes and organized crime.