A SHIPMENT of diamonds from Angola has been seized by Belgian authorities in Antwerp at the request of De Beers,, the Financial Times reported on Thursday. The shipment of rough diamonds was destined for De Beers’s rival, the Angola Selling Corporation (Ascorp). De Beers has said it has contracts to buy all the diamonds from Angola’s Cuango valley produced by SDM – a joint venture between Ashton Mining of Canada, Endiama, the Angolan state mining company, and Odebrecht of Brazil. But the Angolan government recently signed an agreement with Israeli businessman Lev Leviev for the exclusive marketing rights of all diamonds produced in Angola. De Beers said a week ago it would take legal steps to ensure Angola abided by a contract to supply it with the full production of diamonds from the mine.