Some Hindu temples have hundreds of kilograms of gold on their structure, in their secret chambers and treasuries. Every local bank in India has got private lockers with kilograms of gold which are not audited. Family businesses in Indian often don't entrust their gold with banks. Rather they would store them in their private safety lockers. Banks and fintech companies also collect and lend money to the distressed and often end up either auctioning it off or confiscating them.
The amount of unaudited gold will be at least 10 times what is audited officially by governments.