A Nepali spiritual leader believed by his followers to be a reincarnation of Buddha is under investigation over the disappearance of several devotees, police in Kathmandu have said.

Ram Bahadur Bomjan, known as “Buddha boy”, became famous in 2005 after followers said he could meditate motionless for months without water, food or sleep in Nepal’s jungles.

The 28-year-old has a devout following but has been accused of physically and sexually assaulting some of his followers. Special police investigators have begun inquiries after the families of four devotees allegedly vanished from his ashrams.

“The police have started investigating these complaints against Bomjan,” said Uma Prasad Chaturbedi, a spokesman for Nepal’s Central Investigation Bureau. “The investigation is in preliminary stage and we cannot share many details.”

Bomjan has long been dogged by accusations of abuse, even as thousands of worshippers queued for days to witness his “miracles of meditation” deep in the jungle.

In September last year, an 18-year-old nun accused him of raping her at one of his ashrams. Dozens more have filed complaints against him alleging assault. Bomjan said he beat them for disturbing his meditation.

The Bodhi Shrawan Dharma Sangha, an organisation associated with Bomjam, recently claimed fresh allegations made by a local website were baseless. Setopati.com published reports detailing alleged cases of disappearances, sexual assault and violence in Bomjan’s ashrams.