Core Mining and Minerals Resources Limited -- a partner with Marange Resources in the defunct Canadile Miners joint venture -- has approached the High Court challenging their "exclusion" from diamond mining in Chiadzwa.
They also want an order blocking cancellation of Core Mining's seven directors' work permits and reinstatement to their positions in Canadile.
Core Mining says it owns 50 percent of Canadile.
Directors Arslanian Wiken, Licht Yehudah, Subithry Naidoo, Allan John Sawyer, Karen Mikirayan, Komalin Packirisamy and Marco Saveiro Chiotti have all received letters from the Immigration Department informing them of the intention to cancel their work permits.
However, the company says this is a violation of the joint venture agreement between Core Mining and Marange Resources.
Zimbabwe Mining Development Corporation, Minerals Marketing Corporation of Zimbabwe, Marange Resources, Canadile Miners and the Minister of Mines and Mining Development were cited as respondents in the application.
In an urgent chamber application filed at the High Court on Thursday by lawyers Chikumbirike and Associates, Core Mining seek restoration of the status that obtained before their "exclusion" from the business.
The letters from Principal Director of Immigration, Mr Evans Siziba, on October 21, 2010 state that the directors' employer had advised them that their services were no longer required and their work permits should be cancelled.
The directors fear that diamonds worth millions of dollars might be sold without their knowledge and so the matter should be treated with urgency.
In an affidavit, Core Mining director Mr Lovemore Kurotwi said: "ZMDC, the sole shareholder of Marange Resources, has expressly repudiated the agreement by seeking the cancellation of the work permits of the aforementioned persons, despite clear provisions that it is obligatory that those persons be so employed or associated with Canadile."
He added that Marange Resources was merely a shareholder and cannot make decisions for the whole of Canadile without Core Mining's consent.
Mr Kurotwi said there was no board resolution to cancel the directors' permits.
He maintained that there was no court order winding up Canadile's operations.
The matter is yet to be set down for hearing at the High Court.
ZMDC, Marange Resources, the Mines Minister and MMCZ are yet to respond to the application.