Lawrence Hughes, the father of a 17-year-old Jehovah's Witness girl who was the subject of legal battles over her leukemia treatment, plans to sue the church for billions.

Hughes said he and his lawyer plan to file a class-action lawsuit against the Watch Tower Society, the legal organization in use by Jehovah's Witnesses.

He alleges that the society arranged for his daughter, Bethany Hughes, to be moved for treatment of leukemia when she wasn't well, endangering her life.

Bethany died of the disease Thursday at the Cross Cancer Clinic in Calgary.

• Background on Jehovah's Witnesses teachings

"I'm holding the Watch Tower Society responsible," Hughes told reporters in Edmonton. "The church said they had nothing to do with this. Lies, lies and more lies."

Hughes said his lawyer Bob Calvert has not yet filed legal papers, but would likely seek "billions" in damages from the society on behalf of litigants worldwide.

"We haven't worked out the details yet," Hughes said, noting the suit would cite as reasons wrongful death, alienation of family, deceit, misinformation, and "destroying families."

Hughes said he would also seek custody of his other daughter.

During the news conference, Hughes was interrupted several times by David Gnam, a lawyer for his daughter Bethany.

Gnam denied the claims, saying the group did what was in the best interests of the girl and did not try to keep Hughes from seeing Bethany while she was receiving leukemia treatment.

"You were informed weeks ago where she was," Gnam said. "You knew she was here at the Cross Cancer Clinic, she inviting you to come visit her two weeks ago and you refused."

Hughes denied Gnam's version of events, saying he didn't even have a phone number where his daughter could be reached. Hughes then accused Gnam of representing the society, not his daughter.

The high-profile issue over Bethany's treatment split the Hughes family earlier this year after the father consented to the blood transfusions when Bethany was first diagnosed. Bethany, along with her mother and sister, moved out of the Calgary family home last June.

Eventually, the bitter case end up in the court. Judges consistently went against the findings of psychiatrists and bioethicists who argued that Bethany was a mature minor. The courts awarded the province temporary custody under Alberta Child Welfare Act.

The courts concluded that the teen was pressured by her religion to refuse the transfusions and that she didn't have a free, informed will.

Jehovah's Witnesses are taught that the Bible that blood transfusions are against God's wishes.

Without intensive chemotherapy and blood transfusions, doctors gave Bethany a 40 to 50 per cent chance of beating the cancer.

She struggled with staff during the dozens of transfusions that were administered to her in Calgary. After four months of treatments, cancerous lesion appeared on her back and doctors said it was unlikely she would survive.

At first, Bethany told that court that her refusal to accept blood was for religious reasons. But months into her ordeal, she said her fight had become about a teen's right to choose medical treatment.

"My case is about rights," she told a provincial court in July. "We live in this great country called Canada -- a country where all its citizens can live the way they want to, go where they want to.

"They have freedoms -- the Charter of Rights and Freedoms . . . but if you are under 18 you don't fall under citizen any more. They take it away."

A private funeral will be held for Bethany in Calgary on Sept. 12.