The Secret Swami might have veered towards the amusing - in an "Oh my God, how gullible can you be?" kind of way - had it not been for the repeated allegations of sex abuse.
Sai Baba, the swami in question, had started off looking like some old bloke with an ego as big as his bank account. There he sat, in his opulent ashram at Puttaparthi, near Bangalore, dressed in blinding canary-yellow and sporting a head of what looked like jet-black pubic hair - a mane of Leo Sayer proportions; as if he had poked his tongue into a light socket. Count your blessings - he didn't sing.
Instead, he did tricks, producing trinkets from his fingers - gold watches, bracelets, stuff with Ratners written all over it. Maybe he'd read the Paul Daniels Trickster's Guide to Palming, and practised like mad without the distraction of the lovely Debbie McGee (it later transpired that Debbie would not have been a distraction). The swami's followers adored his "miracles" and gasped.
Ten thousand worshippers formed a permanent camp inside the ashram, believing Sai Baba to be an avatar - a god on Earth. He attracted attention from burned out hippies, the ones with smoke still doping their nostrils. Sometimes they smiled their faraway smiles; sometimes they spoke. One guy believed he'd been in communion with Sai Baba for 21 years before he'd visited "god" in his pad. Sai Baba was quick to spot white faces wearing dollar signs. As these dupes gawped up from the crowd, he would single them out for special attention.
The documentary took a much less wide-eyed approach than Sai Baba's flock, denouncing him from the start as a sham whose ashram resembled a market place, not a shrine. Oh yes, he appeared to have done some good - constructing a hospital in the district, providing free medicare for the poor, and supplying clean water - however, the £40 million it cost was funded by wealthy acolytes, faithfully following Sai Baba's earnest exhortation: "Wherever you see a sick person - there is your field of service." And yet, Sai Baba's secret motto turned out to be different, more like: "Wherever you see a gullible young believer, (boys only apply) bingo! - sexual opportunity."
The programme gathered American former devotees who claimed that Sai Baba had abused them, had exposed himself to them, indulged in oral sex and then sworn them to secrecy. This sexual degradation had shaken their faith. These victims included a father and a son who were alleged to have been abused over many years. It was implied that many Indian boys had also been taken advantage of but were too scared to make public statements.
All this would matter if it affected just one child. What makes it worse is that Sai Baba has a worldwide following of 160 million people and is visited by heads of state. He is thus respectable, a notable Indian figure.
The allegations went unanswered. When duly challenged, a twitchy Indian government minister blew his top and accused the reporter of impertinence. Meanwhile the US embassy's website has posted warnings to potential visitors.
Whether or not it will shake the blind faith of the devotees remains to be seen. However, the programme was an example of investigative reporting all too rare these days - getting inside and under the issue. It may have even stopped further innocents from falling prey to the avatar's whim.