I am not usually interested in linking to news articles, but in this case I am intrigued. Apparently there has been a documented case of "self-mummification" by a Mongolian monk which a living monk and the physician to the Dalai Lama described as being a practice of assisted suicide called "tukdam."
"I had the privilege to take care of some meditators who were in a tukdam state.
If the person is able to remain in this state for more than three weeks—which rarely happens—his body gradually shrinks, and in the end all that remains from the person is his hair, nails, and clothes. Usually in this case, people who live next to the monk see a rainbow that glows in the sky for several days. This means that he has found a 'rainbow body'. This is the highest state close to the state of Buddha."
Feb 6, 2015 Smithsonian
"I had the privilege to take care of some meditators who were in a tukdam state.
If the person is able to remain in this state for more than three weeks—which rarely happens—his body gradually shrinks, and in the end all that remains from the person is his hair, nails, and clothes. Usually in this case, people who live next to the monk see a rainbow that glows in the sky for several days. This means that he has found a 'rainbow body'. This is the highest state close to the state of Buddha."
Feb 6, 2015 Smithsonian