Zimbabwe's government on Friday dismissed reports that diamonds were being smuggled into neighbouring South Africa by a Zimbabwean company as "politically motivated rumours" cooked up by its enemies, who had an agenda of regime change.

"Absolute nonsense," commented Amos Midzi, Minister of Mines and Mineral development, in reaction to reports that the European Commission, the incoming chair of the Kimberley Process, an international governmental certification scheme set up in 2003 to prevent trade in conflict diamonds, had summoned executives from River Ranch Limited, a diamond mine in the southern border town of Beitbridge, to respond to allegations of smuggling made by the World Diamond Council (WDC).

Last month, the New York-based WDC said it had received reports that Zimbabwean diamonds were possibly being combined with blood diamonds from the Democratic Republic of Congo (DRC) and smuggled into neighbouring South Africa, where they were being certified as legitimate and exported.

WDC Chairman Eli Izhakoff said he had written to Karel Kovanda, the EC official who took over chairmanship of the Kimberley process on 1 January 2007, informing him of the reports.

According to Midzi, "We are aware that somebody - a sworn enemy of the people of Zimbabwe - is setting an agenda to give the heavily biased European Union reason to extend its illegal sanctions on our government when it sits for a review in February."

The EU imposed targeted sanctions on Zimbabwe in February 2002 after Harare expelled its election observer team. It has since renewed the sanctions, which include a travel ban on senior ZANU-PF officials.

"The claims come as no surprise to us," Midzi told IRIN. "We know the West wants regime change here, but lies will not bring it ... We went to the said mine and made our own investigations, and we established that nothing of that sort has ever happened or was happening. Our enemies also say there is illegal smuggling of diamonds from the Marange belt [in the eastern province of Manicaland] in Mutare [a town on the Mozambican border] into Mozambique and South Africa, yet it is not true."

River Ranch officials have denied the allegations made by the WDC. The company's legal advisor, George Smith, said his mine was innocent and confirmed that they had a scheduled meeting with EC representatives.

"Since the resuscitation of River Ranch Limited in 2004, which went into liquidation in 1998, we have not exported any diamonds, and I wonder where reports and suspicions of diamond smuggling by our company come from - they are simply not true," he told IRIN.

"And it is also not true that it is the EU which has sought an audience with us. In fact, it is us who have called them to clarify issues to them, since there are such allegations leveled against us. We have a meeting with them later today [Friday]."

A number of ruling ZANU-PF party members are shareholders in River Ranch Limited, notably Solomon Mujuru, husband of the country's vice-president, Joyce Mujuru, and some of the more than 100 government officials and associates banned from travelling to Europe by the EU.

Midzi stressed recent attempts to clean up the mining sector. The government claimed it had tamed the illicit extraction of minerals in a crackdown on illegal gold and diamond mining, codenamed Chikorokoza Kwete (No to illegal mining).

Thousands of people, including foreigners from as far as Pakistan and Israel, have been arrested for illegal panning of gold and diamonds in the clean-up operation, while some have been intercepted at exit points as they tried to leave the country with precious stones.

Zimbabwe has been linked to the illegal diamonds in the DRC in the past. About five years ago, the United Nations Panel of Experts on the Illegal Exploitation of Natural Resources and Other Forms of Wealth of the DRC said Emmerson Mnangagwa, a former Speaker of Parliament and National Security Minister, and Zimbabwe Defence Force Commander Gen Vitalis Zvinavashe had enriched themselves from the country's mineral assets under the pretext of arrangements set up to repay Zimbabwe for military services.

Anti-blood diamond trade campaigners do not rule out the continued existence of links between the DRC and Zimbabwe. Zimbabwe provided military support to the Laurent Kabila government in DRC when it battled rebels backed by Uganda and Rwanda in the late 1990s.

The British-based nongovernmental organisation (NGO) Global Witness, which has highlighted the use of resources, such as timber, oil and diamonds, to fund conflicts and corrupt regimes across the world, said the diamond sector in the DRC was riddled with problems.

"DRC is a member of the Kimberley process, but quite a lot of smuggling of diamonds in and out of DRC still goes on," said Carina Tertsakian of Global witness, naming Angola as one of the countries linked to the smuggling.

She pointed out that people in the DRC still spoke of the war that had linked it with Zimbabwe, and the close relationship between Zimbabwean President Robert Mugabe and late President Laurent Kabila. "They talk about some of the links still being active."