Zambia's new President Michael Sata has halted all metal exports from Africa's biggest copper producer, documents showed on Thursday, in a move to ensure that mining firms accurately report their sales.
The mines ministry made the announcement in a circular dated Wednesday, saying: "All current permits issued by my ministry are immediately suspended pending issuance of new guidelines by the government."
Mines ministry permanent secretary Godwin Beene said in the circular that the new rules on metal exports should be ready by October 16.
As the world's seventh-largest copper producer, the metal accounts for 85 percent of exports, but cobalt, lead, gold, silver and emeralds are also mined.
"What the government is trying to do is improve the reporting of its trade flow, and probably by extension also the mining activity, which will probably end up with tax payments," said Leon Myburgh, sub-Saharan African strategist at Citi Group.
"There does seem to be some doubt about how much copper is being produced and exported," he told AFP in Johannesburg.
"The initiative to better capture data regarding copper production and exports is certainly a healthy step for the country," he said, but added that Sata's government was creating uncertainty with its abrupt communication of decisions and policies.
The International Monetary Fund has also said the government needs to tax mining more effectively in order to fund development projects, and Standard & Poor's on Thursday reaffirmed its long-term ratings at B+.
The ratings agency called Sata's electoral victory "an indication of a maturing of democracy in Zambia."
"However, President Sata's victory has increased economic-policy uncertainty in Zambia. A long-standing opposition figure, he has supported changing regulation and taxation of the mining sector," it said.
Investigations into mining tax payments this year have already resulted in the European Investment Bank, the EU's financial arm, freezing future loans to Swiss mining giant Glencore over concerns about tax evasion in Zambia.
Glencore has denied any wrongdoing.
During the election campaign, Sata's Patriotic Front promised to change the mining tax regime to focus on companies' total revenues, rather than profits.
That formula is easier for the country's cash-strapped authorities to regulate, since it taxes a company's bottom line without considering its costs or investments -- which are self-reported and harder to audit.
Sata took office on September 23 vowing transform Zambia's fortunes within 90 days, and wasted little time in putting his mark on the government that had been run by the Movement for Multiparty Democracy for the last 20 years.
Nearly two thirds of Zambians live on less than two dollars a day, and Sata has vowed to ensure that the poor benefit from the booming economy, which grew 7.6 percent last year on the back of strong mining growth.
On Monday, Sata cancelled a $5.6-million sale of a private bank to South Africa's First Rand.
He has also removed the respected Bank of Zambia governor Caleb Fundanga, unsettling the financial sector, and fired the head of the anti-corruption watchdog who was accused of bungling graft investigations.