In January 2002, the Office of the Compliance Advisor/Ombudsman (CAO) for Miga and the International Finance Corporation (IFC) received a complaint from Leat, a Tanzanian NGO, on behalf of a group of Tanzanian artisanal miners.

The complaint alleged that Miga had violated its policies in issuing a guarantee in support of Barrick Gold, the operator of the Bulyanhulu mine in Tanzania.

The CAO summary report, issued on October 21, 2002, after extensive investigation, found that the mine is performing to environmental and social standards that are in line with those expected of an investment of the World Bank Group. The CAO did not find that the project merits a compliance audit, did not find that an independent inquiry was merited, nor that it could play any further useful role in this case.