Tanzanian President John Magufuli called for a special audit of mining companies to verify if they pay their fair share of taxes, Reuters reported March 29.
The order follows a recent ban by the government on exports of gold and copper concentrates.
Acacia Mining plc is in talks with the government over the export ban as the miner's gold and copper concentrate exports remain halted since it was announced. The ban has also cost the firm over US$1 million per day in revenues at its Bulyanhulu and Buzwagi mines.
Export-bound mineral concentrate shipments were also ordered to be placed under 24-hour police surveillance to verify if there are any declaration issues.
In addition, Magufuli instructed officials to seize over 250 shipping containers of gold and copper concentrate owned by Acacia Mining at the Dar es Salaam port pending a tax investigation.
Acacia, however, disputed claims that it was trying to export such concentrates despite the ban, adding that concentrate revenue is included in the company's royalty payment declarations and income tax returns to the Tanzania Revenue Authority.
The company added that its Bulyanhulu and Buzwagi operations are lawfully permitted to export concentrates and have been in full compliance with policies.