24 April 2011 Last updated at 05:03 GMT 
Sai Baba was estimated to have millions of devotees around the world
To his devotees, Sai Baba was an avatar, an incarnation of God in human form, who appeared on Earth to preach his inspirational message in one of India's poorest corners.
To his critics, he was a fraudster dogged for years by controversial allegations of sexual abuse yet protected from prosecution by virtue of his powerful political sway.
Whatever he was, there was no doubt that over time he rose in prominence to become India's premier "god-man", eclipsing the likes of Maharishi and Shri Rajneesh who had first drawn Westerners east in the Sixties and Seventies.
A petite, softly spoken man dressed in full length saffron robes and perpetually sporting a trademark afro hairstyle, Sai Baba's appeal was not limited to Western hippies but cut across Indian society from its lowest to highest echelons as well as spreading to many other countries beyond.
'Immaculate conception' Satya Sai Baba was born Sathyanarayana Raju on 23 November 1926 in the remote village of Puttaparthi in the south Indian state of Andhra Pradesh, although like many born at this time, there is no proof of his date of birth.
Stories abound of the early signs of his divinity.
It is said that his mother claimed her son was born out of an immaculate conception just as Jesus Christ had been, another messiah who Sai Baba often identified himself with.
On another occasion, he was alleged to have survived a scorpion bite and on his recovery, was miraculously able to speak Sanskrit, a language he did not know before. Indeed, throughout his childhood, he was said to have been abnormally gifted in artistic pursuits such as music, dance, drama and writing.
Sai Baba had a huge following When he was 13 years old, the young boy announced to his family that he was the incarnation of Shirdi Sai Baba, a 19th century Indian holyman who had been equally venerated by Hindus and Muslims alike. Changing his name was a key spiritual metamorphosis.
The teenage Sai Baba soon began to attract followers and by 1950, had constructed an ashram called Prasanthi Nilayam (Abode of Peace) near his village to accommodate them.
It heralded the start of the transformation of Puttaparthi into a Sai Baba wonderland spread over some 10 square kilometres; the vast complex of hotels, resorts, university buildings, speciality hospital, airport and enormous ashram thronged with devotees that I witnessed while making the documentary.
Non-dogmatic Part of Sai Baba's huge global popularity may be explained by his non-dogmatic, non-doctrinal approach to spirituality.
In contrast to many sects, followers were not required to give up their previous religious beliefs as the guru stated that he believed in the one God that lay behind all religious paths.
Certainly, Sai Baba inspired love and admiration.
During our time spent filming at the ashram, devotees from around the world would volunteer stories about how Sai Baba had visited them in a dream or had called to them though moments of curious serendipity.
In addition, his mystical ability to manifest vibhuti (holy ash), food as well as jewellery and watches out of thin air was often cited as further proof of his divinity and akin to the 'miracles' ascribed to other past prophets.
His opponents, however, refuted this to me.
In the Secret Swami, I was shown how these manifestations could easily be explained by illusionists' techniques and sleight of hand tricks.
A hospital in Puttaparthi set up by Sai Baba For decades, various scientists, rationalists and magicians have in turn, attempted to challenge the guru to perform his 'miracles' under controlled conditions.
Sai Baba always refused to submit to these tests, once saying: "Science must confine its inquiry only to things belonging to the human senses, while spiritualism transcends the senses. If you want to understand the nature of spiritual power you can do so only through the path of spirituality and not science."
Sexual Abuse The most damning allegations against the "god-man", however, concern the sexual abuse of young boys and male adults during private interviews with him.
Damaging rumours have circulated since the seventies of the guru's sexual exploits but have always been dismissed out of hand by the tightly controlled Sai Baba organisation.
We interviewed the Rahm family in America who had been Sai Baba devotees for years. Both father and son stated that they had been subjected to Sai Baba rubbing oil on their genitals.
"He took me aside," said Alaya Rahm, "put the oil on his hands, told me to drop my pants and rubbed my genitals with oil. I was really taken aback."
Sai Baba counted former Indian prime ministers as his followers Dr Michael Goldstein, chairman of the international Sai Baba organisation, admitted he had heard rumours, but told us that he did not believe them. He said: "My heart and my conscience tell me that it is not possible."
Sai Baba was never investigated on this issue. All attempts to prosecute him failed.
Nor was there any satisfactory resolution to the gruesome killing of four male devotees in 1993 who allegedly entered Sai Baba's bedroom, armed with knives.
The police claimed they had been shot in self-defence.
The lack of any legal proceedings against the guru was perhaps not surprising in light of the level of influence that he commanded.
A previous Indian prime minister, Atal Vajpayee, once issued a letter on his official notepaper calling the attacks on Sai Baba "wild, reckless and concocted".
Since 2005, Sai Baba's health had been deteriorating. Although he once predicted he would die in his mid-90s, he also claimed he could choose the moment of his death.
In death as in life, he remained an enigma to the last.
Tanya Dutt is a London-based radio and television broadcaster and writer. She made Secret Swami, an investigative documentary on Sai Baba for BBC Two.
Obituary: Indian guru Sai Baba
Sai Baba was estimated to have millions of devotees around the world Sri Satya Sai Baba, India's revered spiritual guru who counted presidents, prime ministers, judges and generals amongst his millions of followers around the world, has died at the age of 84.
Until the last, he was a man who inspired passionately conflicting emotions (as I discovered when I made a BBC investigative documentary about him in 2004 called Secret Swami). To his devotees, Sai Baba was an avatar, an incarnation of God in human form, who appeared on Earth to preach his inspirational message in one of India's poorest corners.
To his critics, he was a fraudster dogged for years by controversial allegations of sexual abuse yet protected from prosecution by virtue of his powerful political sway.
Whatever he was, there was no doubt that over time he rose in prominence to become India's premier "god-man", eclipsing the likes of Maharishi and Shri Rajneesh who had first drawn Westerners east in the Sixties and Seventies.
A petite, softly spoken man dressed in full length saffron robes and perpetually sporting a trademark afro hairstyle, Sai Baba's appeal was not limited to Western hippies but cut across Indian society from its lowest to highest echelons as well as spreading to many other countries beyond.
'Immaculate conception' Satya Sai Baba was born Sathyanarayana Raju on 23 November 1926 in the remote village of Puttaparthi in the south Indian state of Andhra Pradesh, although like many born at this time, there is no proof of his date of birth.
Stories abound of the early signs of his divinity.
It is said that his mother claimed her son was born out of an immaculate conception just as Jesus Christ had been, another messiah who Sai Baba often identified himself with.
On another occasion, he was alleged to have survived a scorpion bite and on his recovery, was miraculously able to speak Sanskrit, a language he did not know before. Indeed, throughout his childhood, he was said to have been abnormally gifted in artistic pursuits such as music, dance, drama and writing.
Sai Baba had a huge following The teenage Sai Baba soon began to attract followers and by 1950, had constructed an ashram called Prasanthi Nilayam (Abode of Peace) near his village to accommodate them.
It heralded the start of the transformation of Puttaparthi into a Sai Baba wonderland spread over some 10 square kilometres; the vast complex of hotels, resorts, university buildings, speciality hospital, airport and enormous ashram thronged with devotees that I witnessed while making the documentary.
Non-dogmatic Part of Sai Baba's huge global popularity may be explained by his non-dogmatic, non-doctrinal approach to spirituality.
In contrast to many sects, followers were not required to give up their previous religious beliefs as the guru stated that he believed in the one God that lay behind all religious paths.
Certainly, Sai Baba inspired love and admiration.
During our time spent filming at the ashram, devotees from around the world would volunteer stories about how Sai Baba had visited them in a dream or had called to them though moments of curious serendipity.
In addition, his mystical ability to manifest vibhuti (holy ash), food as well as jewellery and watches out of thin air was often cited as further proof of his divinity and akin to the 'miracles' ascribed to other past prophets.
His opponents, however, refuted this to me.
In the Secret Swami, I was shown how these manifestations could easily be explained by illusionists' techniques and sleight of hand tricks.
A hospital in Puttaparthi set up by Sai Baba Sai Baba always refused to submit to these tests, once saying: "Science must confine its inquiry only to things belonging to the human senses, while spiritualism transcends the senses. If you want to understand the nature of spiritual power you can do so only through the path of spirituality and not science."
Sexual Abuse The most damning allegations against the "god-man", however, concern the sexual abuse of young boys and male adults during private interviews with him.
Damaging rumours have circulated since the seventies of the guru's sexual exploits but have always been dismissed out of hand by the tightly controlled Sai Baba organisation.
We interviewed the Rahm family in America who had been Sai Baba devotees for years. Both father and son stated that they had been subjected to Sai Baba rubbing oil on their genitals.
"He took me aside," said Alaya Rahm, "put the oil on his hands, told me to drop my pants and rubbed my genitals with oil. I was really taken aback."
Sai Baba counted former Indian prime ministers as his followers Sai Baba was never investigated on this issue. All attempts to prosecute him failed.
Nor was there any satisfactory resolution to the gruesome killing of four male devotees in 1993 who allegedly entered Sai Baba's bedroom, armed with knives.
The police claimed they had been shot in self-defence.
The lack of any legal proceedings against the guru was perhaps not surprising in light of the level of influence that he commanded.
A previous Indian prime minister, Atal Vajpayee, once issued a letter on his official notepaper calling the attacks on Sai Baba "wild, reckless and concocted".
Since 2005, Sai Baba's health had been deteriorating. Although he once predicted he would die in his mid-90s, he also claimed he could choose the moment of his death.
In death as in life, he remained an enigma to the last.
Tanya Dutt is a London-based radio and television broadcaster and writer. She made Secret Swami, an investigative documentary on Sai Baba for BBC Two.
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