Researchers examining a nearly 1,000-year-old statue of Buddha on display in Holland discovered something very unusual hidden inside: the mummy of a meditating monk.

Calling the mummy its “oldest patient ever,” the Meander Medical Center in the Dutch city of Amersfoort used a CT scanner to take images of the body inside the statue and an endoscope to examine the thoracic and abdominal cavities.

The mummy is believed to be that of Liuquan, a Buddhist monk who died in China around 1,100 A.D. During their examination, the researchers found that the mummy’s internal organs had apparently been removed and the space filled with “paper scraps that were printed with ancient Chinese characters,” the hospital said in a news release.

The statue was on display as part of the “Mummies: Life Beyond Death” exhibition at the Drents Museum in the Netherlands last year, and this was the first time it had been let out of China.

A brochure from the event says this may be a case of self-mummification.

These monks would typically subsist on water, seeds and nuts for 1,000 days, then roots, pine bark and a toxic tea made from sap of the Chinese lacquer tree for another 1,000 days while sealed inside a stone tomb, according to CNET.

They would breathe through a small tube and ring a bell to let everyone know they were still alive, Business Insider Australia reported. Once the ringing stopped, they’d be left inside for another 1,000 days.

Those who were mummified are said to have achieved enlightenment, Smithsonian reported.

It’s not clear whether Liuquan self-mummified, but the removal of the organs and presence of scraps of paper suggest that may not have been the case.

The statue is now on display in Hungary at the Natural History Museum.