(CNN) -- Two leaders of a Canadian polygamist sect were arrested Wednesday and charged with polygamy in what could be a landmark case, said Wally Oppal, attorney general of British Columbia.
Winston Blackmore, 52, and James Oler, 44, were taken into custody in Bountiful, a western town of about 1,000 residents, Oppal said.
Blackmore has married 19 women and Oler married five, the official said.
The men are members of the polygamist sect known as the Fundamentalist Church of Jesus Christ of Latter Day Saints or FLDS church, he added.
Oppal said such cases have proven difficult for authorities to win. "The problem has always been the defense of religion has always been raised," he said, referring to the Canadian Charter of Rights and Freedoms.
Enacted in 1982, the charter guarantees freedom of religion and has been used twice to get polygamy charges thrown out.
That hasn't happened here. "This could be a groundbreaking case," Royal Canadian Mounted Police Sergeant Tim Shields told CNN in a telephone interview. "It's the first polygamy case in Canada since the enactment of the charter, which usually takes precedence over our criminal code."
He said that the investigation, which began in 2005, included police interviews with more than 90 FLDS followers in British Columbia, Utah, Idaho and Nevada.
Many of the "brides" in the Canadian sect are 15 and 16-year-old girls from the United States, Shields said.
The legal age of consent in Canada is 16, though it rises to 18 in cases where the other person -- such as Oler or Blackmore -- is an authority figure, Shields said.
First court appearances are scheduled for Jan. 21, in the neighboring town of Creston, British Columbia.
Last June, Opal called for a special prosecutor to look into allegations of sexual abuse and sexual exploitation of girls in the Bountiful community.
"We keep hearing about many young girls who have established relationships with much older men," Opal told reporters then.
At Opal's request, two lawyers have written opinions on the matter, both concluding it would be difficult to pursue criminal charges and one saying it would be unfair to do so, according to Opal's office.
Opal said he is in no rush. He cited the recent massive investigation by U.S. authorities into the FLDS sect in Eldorado, Texas, where more than 440 children were seized from the group's compound in April after allegations surfaced of sexual and physical abuse.
However, a district judge signed an order allowing the children to return to their parents after the Texas Supreme Court affirmed that the state had no right to remove them during the raid.
The FLDS is not affiliated with the mainstream Mormon church, which renounced polygamy more than a century ago.
-- CNN's Juliana Silva contributed to this report.