Tens of millions of dollars have been diverted in India from schemes to fight poverty and used to fund Delhi's Commonwealth Games, a report says.
The Housing and Land Rights Network pressure group says its report is based on official documents obtained under India's right to information act.
The group says there should be an independent inquiry into how this was allowed to happen.
Government officials in Delhi say they are looking into the allegations.
This report is a damning indictment of the way the Commonwealth Games have been financed and planned by the central and state governments.
It says tens of millions of dollars have been diverted from funds which are supposed to help raise underprivileged low caste communities out of poverty.
The report also says spending on the Games has spiralled out of control: expenditure on sports infrastructure alone is more than 2,000% of the initial projected budget.
In addition, more than 100,000 poor families have already been evicted due to projects connected with the Games, and up to 40,000 families are likely to be displaced before the Games begin in October, the document says.
The report's author, Miloon Kothari, a former UN human rights rapporteur, told the BBC that the evidence was clear.
The determination, he said, to portray Delhi as a world-class city and an international sports destination, had led the government to lose sight of its legal and moral commitments to its people.