In the latest twist to the long saga of the Mir space station, biologists have stated their concerns about the fungi the platform will bring back to Earth when it splashes down this month.

Russian NTV television interviewed Yuri Karash, a space expert who thinks the organisms, which have spent 15 years quietly mutating in their own isolated environment on Mir, could be a real problem.

The micro-organisms mutated from fungus found on Earth

"I don't want to be a pessimist," Mr Karash said. "But the problem is there and it is a serious one.

"The mutant fungi do exist and in future they could do serious damage to humanity. We can only draw the final conclusions after we have completed our research."

Over the years, visitors to Mir have consistently said the biggest impression on reaching the station is the smell.

The mutant fungi do exist and in future they could do serious damage to humanity

Space expert Yuri Karash

And they have found various types of fungus growing behind panels and in air-conditioning units.

Some of them corrode metalwork or give off toxic fumes. But it is how they will develop when they reach Earth that is worrying some of these biologists.

Mir is likely to splash down in waters which are New Zealand's responsibility.

Yuri Karash: a worried man

Prime Minister Helen Clark has reassured the nation that there is no radiation or biological hazard on board. But that was before the latest revelation about the fungi.

Scientists have been worried about contamination from space before. Quarantine was a routine precaution for early astronauts.

Neil Armstrong, the first man on the Moon, had to fill in an agriculture, customs, immigration and public health declaration on his return to the United States.

In the section about conditions on board Apollo 11 which might lead to the spread of disease, the astronauts wrote "To Be Determined".

Mir has already entered the upper atmosphere

But perhaps the closest parallel came just last year, when Greenpeace recalled hundreds of promotional mousemats made using materials from the Brazilian rainforests.

It turned out these materials included an unknown type of fungus which caused allergic reactions among users.

Whatever happens, the Russian space agency is not considering postponing the splashdown, which is expected on or around 20 March.

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