Antananarivo - The nearly two-week-long political crisis in Madagascar, the world's biggest producer of vanilla, has raised concerns for exports of the fragrant spice, local media reported Friday.

Madagascar, an island located off south-east Africa, supplies up to 80 per cent of the world's vanilla, and exports of last year's harvest are due to begin shipping this month.

But producers fear that exports could be affected if the unrest that began in the capital Antananarivo last week, when tens of thousands of people demonstrated against President Marc Ravalomanana's rule, continues, Midi Madagasikara newspaper reported.

Although dwindling in size, the protests that degenerated last week into looting and rioting are continuing.

"A delay in exports could negatively influence our (sales) campaign," an industry official told the newspaper.

Vanilla is a flavoring derived from orchids of the genus vanilla, that is native to Mexico.

In Madagascar, the flowers have to be artificially pollinated by hand, unlike in Mexico, where it is performed by a tiny bee.

The green vanilla pod is harvested between July and September, then heated and dried until it acquires a brownish-black colour and sweet aroma.

This year's vanilla harvest has yielded over 1,200 tonnes of the highest quality spice.

Vanilla is used worldwide in food production. (dpa)