The treasure hunters dug around one of the four pillars of the mandap and tried to lift it, causing the entire structure to collapse.
Police have found farming tools used for the digging at the site in Bellary district, around 372 km from Bangalore.
State tourism minister Anand Singh said, “I have directed the officials of the Archaeological Survey of India to rebuild the mandap and keep all the materials of the collapsed structure in a museum.” Singh said he had asked the police to nab the culprits.
Hampi Mahesh, a member of the Hampi Hitha Rakshan Vedike which fights for protection of the heritage site, on Monday said treasure hunters were repeatedly trying to steal antique pieces.