India's national defence research centre has sponsored a research by a team of military doctors to study an 83-year-old holy man who claims to have spent seven decades surviving without food or water.
The long-haired and bearded yogi, Prahlad Jani, has been sealed in a hospital in the western city of Ahmedabad where he is under 24-hour observation by 30 doctors and will be subjected to a series of medical tests.
"The observation from this study may throw light on human survival without food and water," doctor G. Ilavazahagan, director of India's Defence Institute of Physiology and Allied Sciences (DIPAS), told AFP.
The DIPAS is part of the Defence Research and Development Organisation, India's state defence and military research institute also behind a grenade packed with chilli powder that recently hit headlines.
"This may help in working out strategies for survival during natural calamities, extreme stressful conditions and extra-terrestrial explorations like future missions to the Moon and Mars by the human race," Ilavazahagan said.
The tests on Jani include magnetic resonance imaging (MRI) scans, measuring brain and heart activity with electrodes and other neuro-physiological studies, in addition to blood tests.
The experiment started on April 22 and will take 15-20 days. Since the beginning, Jani has neither eaten nor drunk and has not been to the toilet, Ilavazahagan said.
"The exercise of taking this yogi under the medical scanner is to understand what energy supports his existence," he added, explaining that soldiers could benefit from his apparent ability to survive.
"Jani says he meditates to get energy. Our soldiers will not be able to meditate, but we would still like to find out more about the man and his body," he said.
Neurologist Sudhir Shah, who studied Jani in 2003 and is part of the new experiment, said that the extremely skinny but apparently active man faced round-the-clock observation.
"Two stationary 24-hour video cameras have been set up in his room, while a mobile video camera follows him whenever he needs to step outside," he said.
Jani, who dresses in red and wears a nose ring, grew up in Charod village in the Mehsana district in Gujarat and claims to have been blessed by a goddess aged eight, which has enabled him to survive without sustenance.
Shah said that Jani told him the key to his survival was a mystical and unexplained process by which he receives drops of water through a hole in his palate.
Analysis of data, to determine his secret or expose his fraudulence, will take at least two months, the doctors said.
Fasting is a part of Indian culture, made famous by independence leader Mahatma Gandhi, who brought himself to the brink of death on several occasions by refusing food and water to protest against colonial rule.
A monk from India's minority Jain religion -- devout followers of which undertake frequent fasts, sometimes to death -- claims to have deprived himself of food for one year, which is believed to be a record
"If you're busy with something you don't feel hunger, thirst, or the heat and cold," said Sri Sahaj Muni Maharaj, who took daily glasses of warm water during his fast which ended on May 1998.
"I'm busy contemplating the infinite," he told India's Outlook magazine one month before the end of his experiment.