Zimbabwean police have arrested six directors of two diamond mining corporations on suspicion of fraudulently obtaining a licence.
The officials work for the Zimbabwe Mining Development Corporation and Canadile Miners, state media reported.
They are suspected of fraudulently obtaining a licence to mine the controversial Marange fields, in the east of the country.
Marange is mired in controversy over legal issues and abuse by the military.
The Kimberley Process, a global certification scheme meant to prevent trade in "blood diamonds", has limited sales from Marange after its investigation found soldiers had beaten villagers to force them to mine the gems.
The group is due to meet to review Zimbabwe's efforts to curb abuses by government soldiers.
The state-run Herald newspaper said those arrested included Dominic Mubaiwa, chief executive of the ZMDC, and Lovemore Kurotwi, the local head of Canadile Miners - a joint Zimbabwean-South African venture.
The report said they faced charges of misrepresenting that the joint venture firm was able to fund mining operations in Marange.
"Blood diamonds" are rough diamonds used by rebel groups or their allies to finance wars and conflicts.
The Kimberley Process was set up in 2002 after the diamond trade was accused of fuelling several conflicts in Africa.