The team, which is camping at Hosapate in the mine-rich District, grilled the owners of stock yards of Koppal and Ballari districts, officials said.
Transport and exporters of iron ore were also questioned, they said.
The officials of Forest, Mines and Geology, Transport, and Police departments too were questioned, officials said.
The illegal export from Belekeri port in Uttara Kannada District was exposed by former Karnataka Lokayukta N Santosh Hegde, who in his report, had said 7.74 million tonnes of iron ore were illegally exported between 2006-07 and 2010-11, causing huge loss to the exchequer.