Buttar has been under investigation by the North Carolina State Medical Board for a decade and for a variety of misconducts involving "unconventional treatments" to which he subjects autistic children and cancer patients - all for lots of money to line his pockets. He views the medical board, in his own words, as a "rabid dog."
Ultimately, the medical board has recommended restricting Dr. Buttar's license to prohibit him from treating children or patients with cancer. That hasn’t stopped him (discussed here; for a more neutral assessment go here).
Among his more famous autism treatments is the transdermal chelation cream (a.k.a. “Buttar’s butter”). He has been known to come up with some truly bizarre protocols to treat autism, with rumors that Dr. Buttar's armamentarium of woo even included urine injections to "boost the immune system". Of course the fees are exorbitant.
His cancer quackery is even worse, and Buttar has apparently said that ”it didn't matter what kind of cancer anybody had, he could cure it."
And yes, it is there, all of it: Buttar believes most patients with cancer also have high levels of heavy metals, such as mercury, and other toxins, such as pesticides, because of environmental exposure”. His treatments include chelation, ozone therapy and hyperbaric oxygen chambers – dangerous, potentially lethal devices or regimes with not the slightest trace of evidential support for any claims to efficacy. He even has an AirEnergy Machine.
His website is here: http://www.drbuttar.com/Ar
Buttar is most prominent, however, for being a rabid anti-vaccinationist, running all the usual canards. Remember Desiree Jennings? The gal who claimed to have her walking impaired by the H1N1 vaccine (but got magically cured right after the media forgot about her?) Guess who her accomplice was, the doctor who “diagnosed her and helped her”.
Diagnosis: Crackpot, and a severe case of confirmation bias coupled with belligerence. Very dangerous – many of his treatments are definitely harmful (and hardly beneficial), and they are being used. Should be stopped as quickly as possible.
Btw, his website prominently displays the following quote: "All truth passes through 3 phases: First, it is ridiculed. Second, it is violently opposed, and Third, it is accepted as self-evident." (Schopenhauer). Anyone who uses this quote as support for his or her ideas is a seriously delusional crackpot. That’s a law.
(Come to think of it, it’s a strikingly stupid and magnificently false claim Schopenhauer is making to begin with.)