The criminal trial against two men from a polygamous sect in British Columbia is likely to re-examine whether the ban on multiple marriages violates the right to religious freedom, experts say, despite a court decision three years ago that declared the law constitutional.

Winston Blackmore and James Oler were each charged this week with practising polygamy in a religious commune in southeastern B.C. known as Bountiful.

Blackmore is accused of having 24 marriages, while Oler is accused of four.

Bountiful, whose residents follow a fundamentalist form of Mormonism that still permits polygamy, has been investigated numerous times since the early 1990s, but concerns about whether the polygamy law would withstand a constitutional challenge repeatedly scared off prosecutors.

Many of those questions appeared to be answered in 2011, when a B.C. Supreme Court judge ruled the law did not violate the charter after hearing a constitutional reference case.

Legal scholar expects Charter challenge

But the 2011 decision won't prevent Blackmore and Oler from raising Charter issues at trial, says Nicholas Bala, a law professor at Queen's University in Kingston, Ont.

It is likely that the issue of the constitutionality will be litigated again. —Nicholas Bala, Queen's University

"That was a reference case, which means it was an advisory opinion and not necessarily binding on a trial court," said Bala.

"And it certainly wouldn't be binding on the (B.C.) Court of Appeal or the Supreme Court of Canada, he said. "It is likely that the issue of the constitutionality will be litigated again."

Blackmore and Oler were charged for the first time in 2009, but the case was thrown out over the government's use of a special prosecutor.

The collapse of the case was unrelated to questions about the constitutionality of the polygamy law, but the B.C. government nevertheless took the opportunity to launch the reference case.

The result was an exhaustive trial that heard from academics, former polygamous wives, and several women from Bountiful, who testified anonymously.

Two young girls of the polygamous community of Bountiful walk past the mountains at Bountiful near Creston, B.C., in April 2008. (Jonathan Hayward/Canadian Press)

The judge hearing the case concluded the harms that polygamy poses to society outweighed claims to religious freedom.

Bala, who agrees with the 2011 decision and believes the law is constitutional, said he expects the criminal case to be appealed to the Supreme Court of Canada, whatever the outcome.

While the reference case featured a broad examination of polygamy across North America and around the world, Vancouver-based constitutional lawyer Craig Ferris said Blackmore and Oler's prosecution would be restricted to what they are alleged to have done.

For example, the judge who heard the reference case concluded the law would be unconstitutional if it were used to prosecute a child bride, but that wouldn't apply to Blackmore and Oler.

"There are a number of issues that were raised in the reference case that are unlikely to be raised in this case," said Ferris.

"You'll get a more specific constitutional argument, which again may not answer the question on this law forever, because you will be focusing on the charges that were laid."

Beverley Baines, another Queen's University law professor, said a legal challenge could succeed without arguing about religious freedom.

Baines, who believes the law should be struck down, said the defence could claim there is no proof polygamy is always harmful to women and children.

Students play basketball on April 28, 2008, in the polygamist community of Bountiful near Creston, B.C. (Joe Sales/Associated Press)

"There are too many anecdotal pieces of information that suggest people choose this lifestyle and they're not harmed in the Canadian context," she said.

"It's whether the state can justify [the law]. Can the state say with a straight face that women are harmed when women are prepared to testify they're not?"

Baines said there are other laws that already criminalize the harms often associated with polygamy, such as sexual abuse or child trafficking, and she argued the law could actually hurt women and children in polygamous communities.

"Forcing those folks to hive themselves off in a secret enclaves is a recipe for exploitation and disaster."

No 'simple answer' on effects of polygamy: sociologist

Melanie Heath, a sociology professor at McMaster University in Hamilton, Ont., said she doesn't believe enough is known about polygamy in North American to know whether the practice is inherently harmful.

Heidi Mattingly Foster, a polygamist, leaves the U.S. Federal Courthouse in Salt Lake City, Utah, after observing a hearing on Jan. 17, 2013. Members of the Brown family, who are polygamists and were made famous by the television show "Sister Wives," are suing Utah on the grounds that the state's bigamy laws are unconstitutional. (Jim Urquhart/Reuters)

Heath said that could change as polygamous families become more open about their marriages. She pointed to TV programs such as Sister Wives and legal developments in jurisdictions such as Utah, where a court recently threw out a section of the state's polygamy law. Utah's attorney general is appealing the decision.

"I don't think there is a simple answer," she said.

None of the allegations against Oler and Blackmore have been proven in court.

Oler was also charged with unlawfully removing a child from Canada to commit the offences of sexual interference or invitation to sexual touching. Two other people were also charged with illegally removing a child from the country.

A first court appearance has been scheduled in Creston, just north of Bountiful, on Oct. 9.