Already shaken by a series of high-level defections, accounts of abuse among its staffers, and the high-profile breakup of Tom Cruise and Katie Holmes, the Church of Scientology now faces scrutiny over its controversial drug treatment program, Narconon.Four deaths at Narconon's signature treatment facility in eastern Oklahoma have prompted local law enforcement and health officials to investigate the center and its program. The inquiry began after Stacy Dawn Murphy, 20, was found dead in her room on July 19 after returning to the facility from a one-day leave. The cause of death is under investigation.Two other clients died within the previous nine months. Another died in 2009. In two of those cases, serious health issues were cited; the cause of the other death is unclear.In April, authorities in Quebec shut down a Narconon facility in the city of Trois Rivieres, saying certain treatment procedures "may represent a health risk.''Church of Scientology public affairs director Karin Pouw said there is no suggestion the two investigations "have anything to do with Narconon's methods of drug rehabilitation.'' She said media have misrepresented facts about the Oklahoma investigation, but offered no specifics.As for recent incidents that generated unfavorable publicity for Scientology, Pouw said: "There is no relationship to any of these things, other than the continued growth of the Church and its social and humanitarian programs.''Narconon centers claim success rates of 75 to 90 percent. But their methods, developed by Scientology founder L. Ron Hubbard, have drawn fire over the years. They include high doses of niacin and lengthy sauna sessions that are said to release stored drug residues from fat tissue — a Hubbard theory contested by many health professionals.The Narconon network of treatment centers is part of a Church of Scientology "sector" called the Association for Better Living and Education, or ABLE. It supports and coordinates the church's "social betterment" causes, such as combating drug use, advancing human rights and improving literacy. When Cruise, Scientology's most famous parishioner, said in a 2006 video that Scientologists were "the authorities" on drug treatment, he was talking about Narconon. Parishioners are pressed hard to donate.Now, an unflattering focus on Narconon poses a potential new threat to Scientology's image, which has suffered since defectors began speaking out in 2009 about staffer abuses and overly aggressive fundraising, allegations the church has denied.Narconon's umbrella organization, Narconon International, was founded in 1970 to guide Narconon centers around the world. The nonprofit centers pay Narconon International 10 percent of their revenues, according to documents the church gave the IRS in 1993.Although the church does not file IRS returns, its nonreligious, nonprofit affiliates report income and expenses. Narconon International said in its most recent filing it took in $5.6 million in 2010. The organization said it had 53 residential programs across the world and that more than 2,800 people graduated from the centers that year. An "outcome monitoring" effort found 75 percent of those clients were free of drugs in the year after they left.Three Narconon centers are in Florida — an outpatient center in Clearwater and residential facilities in Spring Hill and Destin. The facilities are licensed by the Department of Children and Families. Recent inspection results were not immediately available for the Clearwater and Spring Hill centers. Inspectors have given the Destin facility consistently high performance ratings since 2010.The Oklahoma facility, known as Narconon Arrowhead, is on Eufaula Lake in Pittsburg County, about 90 miles south of Tulsa. It can treat as many as 150 to 200 clients.The center took in $8.6 million in 2010 and spent $7.9 million on operating expenses and drug awareness efforts, according to IRS filings. It reported helping 529 people with drug rehabilitation services and "life skills courses.''Pittsburg Assistant District Attorney Richard Hull said the Sheriff's Office and state Mental Health and Substance Abuse officials are conducting separate investigations. They are awaiting autopsy findings and toxicology reports in Murphy's death, which are expected by early September.Health officials will explore whether there are grounds to seek an injunction against Narconon Arrowhead, Hull said. The center is cooperating with the investigations, Hull said.Officials are also investigating the deaths of 21-year-old Hillary Ann Holten of Carrollton, Texas; 32-year-old Gabriel W. Graves of Owasso, Okla.; and 28-year-old Kaysie Dianne Werninck of St. Augustine.Holten died on April 11 and Graves on Oct. 26. Holten's autopsy report also has not been completed. Her obituary in the Dallas Morning News said she died of complications from pneumonia and congenital adrenal hyperplasia. The medical examiner could not a find a cause of death for Graves. Werninck died in March 2009 after she was transferred to a Tulsa hospital. Her parents sued Narconon Arrowhead, alleging it gave her the wrong medication and failed to get her proper care after she developed an upper respiratory infection. The family and the center settled the case last year.Narconon Arrowhead director Gary Smith did not respond Wednesday to a request for comment. Nor did Narconon International president Clark Carr.In Quebec, authorities ordered the Narconon in Trois Rivieres to close after inspectors found several newly mandated operational criteria needed corrections. The center was told to move its 32 clients to other Narconon facilities. Most were placed in centers in the United States, the Gazette in Montreal reported.Pouw said Quebec's changes to its laws mandating medical detoxification have not been adopted by other provinces. Narconon facilities remain open there.David Love, 60, told the Tampa Bay Times this week he spent 11 months at the Trois-Riveres center, five months as a client and the following six months on staff.Addicted to painkillers after four back surgeries, he checked himself in on Dec. 1, 2008. The center told clients they should expect a three-month minimum stay, Love said. Cost was $23,000. The center gave Love a discount because he was unemployed, he said.He started in a "withdrawal unit'' with about seven other new arrivals, he said. The clients paired up, sat facing one another at close distance and practiced making eye contact and other drills requiring them to focus.After nine days, he joined longer-term clients in the main unit. Ten days later he began a daily regimen of five-hour sauna treatments and increasing dosages of niacin, which is a form of vitamin B available over the counter. The staff gave him 100 milligrams the first day and upped his dosages 100 milligrams each day thereafter.On his 26th and final day in the sauna, Love ingested 2,600 milligrams of niacin, he said. The niacin treatments concerned him because he suffers from liver fibrosis, he said.The sauna treatments were followed by 3½ months of studying Hubbard teachings familiar to all Scientologists. He said he knew from the start he was in a Scientology environment, but no one pressured him to join the church. He took a job on the center's staff after "graduating'' from the treatment program. He started as a course room supervisor, paid less than minimum wage until he protested, he said. He quit on Nov. 3, 2009, after arguing with supervisors that the center's advertised 70 percent success rate was inflated, he said.Pouw said Love is an extremist who has been trying to generate negative coverage of Narconon. Describing Love as "an anti-Scientologist,'' she said "any statements by him are undoubtedly false.''Joe Childs can be reached at [email protected] Thomas C. Tobin can be reached at [email protected] Information from the Associated Press was used in this report.