Hawkers of MMS 'Miracle Cure' Run Out of Luck in Ireland

— -- While the "clergy" of a fringe church pushing a potentially harmful "miracle cure" for disease has so far managed to skirt the law in the U.S., one of its holy men in Ireland has not been so lucky.

"Bishop" Patrick Merlehan was convicted Thursday in an Irish court of two charges "related to the manufacture and supply of Miracle Mineral Solution (MMS)," which is an unauthorized medicine there, according to a statement from Ireland's Health Products Regulatory Authority (HPRA). He was fined 4,000 Euros.

Merlehan is listed as a "bishop" on the website of the Genesis II Church of Health and Healing, which has been the subject of more than a year-long ABC News' "20/20" investigation. The church was founded by a former Nevada gold prospector named Jim Humble, who claims to have traveled through space, on the idea that MMS can cure or treat virtually any disease or ailment from childhood autism, to cancer, to HIV and herpes.

WATCH the full Brian Ross "20/20" report tonight on ABC at 10 p.m. ET.

Ireland's HPRA said MMS is actually "product which contains a substance which is used in bleach and has no recognisable therapeutic benefits." American officials and medical experts went further in interviews with ABC News.

"This is a poison. This is a high-strength industrial bleach," said Dr. Paul Wang, the senior vice president of Autism Speaks. "It really scares me that people would give this to their kids, because it is a poison."

Tests conducted by ABC News show the "miracle cure" is little more than a chemical that when mixed with citric acid produces chlorine dioxide. Federal prosecutors said it would be useful to clean swimming pools or kitchen countertops but does not cure autism or anything else.

"They might as well be selling Clorox," said Ben Mizer, the U.S. principal deputy assistant attorney general for the Justice Department's Civil Division. "You wouldn't drink Clorox, so there is no reason you should drink MMS."

Mizer was involved in the arrest and indictment of four people in the U.S. related to the sale of MMS in Nevada. Three pleaded guilty and the fourth was sentenced to more than four years in prison in 2015.

But in that case, the four were selling MMS directly to consumers through an online company. The Genesis II Church, however, says it does not sell MMS, but offers its "sacrament" after a donation has been made. One website offered five sets of the MMS chemicals for $95.99.

Mark Grenon, who calls himself an "archbishop" and offers weekend seminars in MMS at hotels in the U.S., claimed in an online video that being part of a church puts him out of the reach of U.S. law.

"The church is under no law. That's why you can go to a church and get political asylum. A priest can give a kid alcohol, a minor, in public, and not get arrested," he said.

When ABC News attempted to ask Grenon about his church, he denied the church was doing anything wrong, stood by the MMS "miracle cure" claims and accused an ABC News reporter of being an "actor" and "pawn" of the pharmaceutical industry.

Still on the MMS trail, Mizer said in an interview that wrapping potentially criminal activity in the cloak of religion won't save anyone.

"They can be prosecuted, yes, if they are selling it in order to cure diseases or are telling people that it will cure diseases," he said.