The android Kannon, based on the Buddhist deity of mercy, preaches sermons at Kodaiji temple in Kyoto, and its human colleagues predict that with artificial intelligence it could one day acquire unlimited wisdom.

"This robot will never die, it will just keep updating itself and evolving," priest Tensho Goto told AFP.

"That's the beauty of a robot. It can store knowledge forever and limitlessly.

"With AI we hope it will grow in wisdom to help people overcome even the most difficult troubles. It's changing Buddhism," added Goto.

The adult-sized robot began service earlier this year and is able to move its torso, arms and head.