Promoters of a so-called "miracle" tonic which claims to have cured most diseases known to mankind can expect a visit from New Zealand health officials.
Genesis II Church of Health and Healing's Miracle Mineral Solution, which is sold online, purports to cure HIV and cancer, among other illnesses.
The non-religious church's website also suggests using it to treat Ebola.
"We can't guarantee that MMS will cure Ebola," the website says, "because we haven't had sufficient opportunity to test it out.
"But for the last 17 years it's cured most every disease known .. so there's a good chance it will do the same with Ebola."
The US church's leader, Jim Humble, is conducting a three day seminar in Ngatea from Friday, on the product's benefits.
But Medsafe says it's once again investigating claims made on a New Zealand website selling the product. It also investigated - and issued a warning to promoters - in 2010.
Anyone using the product should throw it away, Medsafe's Dr Stewart Jessamine says.
"There's absolutely no evidence from well conducted clinical trials that consuming this substance has any role in the treatment of any condition whatsoever," Dr Jessamine says.
"It's been said that the internet is the biggest junk shop in the world with the world's best library. The problem is you don't know whether you're in the library or in the junk shop. In this case we'd say you're in the junk shop."
However, the New Zealand agent for MMS, Roger Blake, says Medsafe has not done any of its own research on the product and is just following America's Food and Drug Administration, which in turn he says, is protecting powerful drug companies.
He says the product has saved the lives of thousands, including some of the 50 people expected to attend this weekend's seminar.