"Zimbabwe is importing yellow maize from Argentina which is known to be GMO - one vessel is coming into port now to offload 7,000 tonnes in Maputo, Mozambique, and 7,400 tonnes in Beira," said one trader.

The trader said another ship was being loaded in Argentina with a similar cargo also destined for Zimbabwe.

Another source who monitors food shipments in the region confirmed the same details to Reuters.

Like many African countries, Zimbabwe is suspicious of GMO foods on the grounds that they have not been adequately tested. In the past it has said it would accept only milled GMO foodstuffs to avoid cross-breeding with local crops.

"This is definitely unmilled, bulk maize," said the trader.

POLICY UNCHANGED

But Security Minister Didymus Mutasa, in charge of land reform, resettlement and food security, told Reuters that he was not aware of the shipment.

"To be honest I have never heard of that. They would have to consult with me but no one has done so. Maybe they might be ordering it for livestock but I don't think so either," he said.

"That policy (against unmilled GMO maize) is steadfast, we continue to maintain it. It has not been reviewed and my (cabinet) colleagues have not changed their position," he said.

What no one denies is Zimbabwe's pressing food needs.

Aid agencies have said about 4.3 million Zimbabweans require food aid until at least the April harvest because of a scorching drought last year.

But critics say Zimbabwe's controversial seizures of white-owned farms for redistribution to landless blacks have also hampered food production.

Maize from Argentina seems to be the flavour of the month.

Even regional breadbasket South Africa has imported some yellow maize from Argentina because it is cheaper than the locally grown product.

The World Food Programme has said higher South African maize prices have forced a rethink in its plans and it is looking elsewhere to buy supplies.

South Africa's March contract for yellow maize closed three rand higher on Friday at 950 rand ($156.4) a tonne.