BANGKOK, Thailand (AFP) – A Buddhist monastery in Thailand is under investigation after authorities discovered more than 40 bodies on site which were allegedly used for meditation practices, police said Sunday.

Forty-one cadavers were found at Pa Nakhon Chaibovorn monastery in Thailand’s Phichit province on Saturday, a senior police officer told AFP.

“The bodies were accompanied with death and body donation certificates,” he said, adding that so far no charges have been filed.

He said police were reaching out to relatives of the deceased to confirm that the bodies were donated willingly.

“We are trying to make sure that none of the dead bodies were stolen,” said the officer who requested anonymity.

The search came days after police discovered 12 bodies at another monastery in neighbouring Kamphaeng Phet province on Wednesday, according to Thai local media.

The head of the Phichit province monastery, Phra Ajarn Saifon Phandito, told Thai PBS television channel that the use of corpses was part of a “meditation technique” he developed.

“Many of the people who come to learn are abbotts and all these monks… pass on the knowledge,” he said.

“I don’t know how many have adopted my technique.”

He also told another local TV station that “practitioners meditate in pavilions that hold coffins with the human remains”.

Phichit police said they are working with authorities in other provinces to investigate how widespread this practice is.