Datta Phuge shot into the global limelight in 2013 when he bought a shirt made with more than 3kg of gold and worth $250,000 (£186,943).
A money lender based in western Pune, Mr Phuge was called "the gold man".
Four persons have been detained for questioning. Police suspect a dispute over money led to the murder.
The police said some 12 people attacked Mr Phuge, 48, in Pune on Thursday night.
One of the suspects had invited Mr Phuge and his 22-year-old son to celebrate a birthday at an open ground in Dighi area when the men attacked him with stones and a sharp weapon.
Police said the son had witnessed his father being murdered and had been spared by the alleged killers.
"However, we are investigating how Mr Phuge reached the open ground where he was murdered," Dighi police station inspector Navnath Ghogare told the Press Trust of India news agency.
India 'gold man' battered to death - BBC News
A money lender based in western Pune, Mr Phuge was called "the gold man".
Four persons have been detained for questioning. Police suspect a dispute over money led to the murder.
The police said some 12 people attacked Mr Phuge, 48, in Pune on Thursday night.
One of the suspects had invited Mr Phuge and his 22-year-old son to celebrate a birthday at an open ground in Dighi area when the men attacked him with stones and a sharp weapon.
Police said the son had witnessed his father being murdered and had been spared by the alleged killers.
"However, we are investigating how Mr Phuge reached the open ground where he was murdered," Dighi police station inspector Navnath Ghogare told the Press Trust of India news agency.
India 'gold man' battered to death - BBC News
