Tanzania seizes diamonds from British mining company
Speaking on government television channel TBC 1, finance minister Philip Mpango said the diamonds extracted from the Williamson Diamonds mine had been "nationalised".
The mine is 75% owned by Petra Diamonds, with the remaining stake held by the Tanzanian state.
The diamonds were seized on August 31 at the airport in Tanzania's main city of Dar es Salaam as they were being shipped to Belgium.
According to Tanzanian authorities, the documents from Williamson Diamonds estimated the value of the shipment at $14.7m based on a lower declared weight, while in fact they were worth double the amount.
"The Williamson Diamonds company documents put the value of the diamonds at $14.7m (before cutting and polishing) while their real value is $29.5m," the finance ministry said in a statement.
Two senior officials in the mining sector who had been cited in parliamentary reports on suspected embezzlement connected with the mining and sale of diamonds resigned following pressure from President John Magufuli.
Nicknamed the Bulldozer, Magufuli swept to power in 2015 on an anti-corruption platform.
He has said government officials implicated in the parliamentary report should resign and not wait for a formal dismissal order.
Magufuli has also locked horns with foreign mining companies which according to a parliamentary report have underreported their production, thus depriving Tanzania of tens of billions of dollars in revenue since 1998.