By Richard Crompton BBC, Tanzania

Does the leopard benefit from the beer?...

A row is brewing between Tanzania's national parks authority and the makers of the country's most popular beers.

Beer brands such as Serengeti and Kilimanjaro, named after the national park and the mountain respectively, sell in their millions.

But the brewers are being accused of cashing in while providing little or nothing towards conservation.

Serengeti has become a byword for conservation, and like Kilimanjaro, is an internationally recognisable symbol.

Moral pressure

Dozens of companies have seen the commercial opportunities of using such powerful brand names.

... this one was too busy to respond

Drinking water, internet services, hotels, and - largest of all - beer companies are among those now being asked to give something in return.

"We feel that, since they are using these names to make money, they should also contribute to the upkeep of these places because if they deteriorate for whatever reason, it means that this will impact on their products as well," says Gerald Bigrube, director-general of Tanzania's National Parks Authority.

The national parks have asked lawyers to investigate whether they can trademark the names of natural resources.

In the meantime, they are relying on moral pressure.