A few months back, suspicious Russian custom officials moved in on two travellers to inspect their luggage.

They turned out to be smugglers, attached to a larger criminal gang. The pair were carrying an impressive array of rare and valuable collectibles including silver antiques, rare books, fossils and ...some 'granite'.

Officials were not inclined to believe that the two 100g rocks being carried were granite for decorating office space - mostly because they looked nothing like granite. But it was not immediately obvious what they really were.

Only after a three month investigation did the officials find out that the rocks were not from Russia at all - at least not originally. They were a couple of pieces of space rock, probably supplied by the same crooked scientists who provided the fossils.

Whilst the exact type of meteorite involved has not been reported, material from outer space can be extremely valuable. For example, a 2.61g piece of meteorite from Mars recently sold for $3,884 - well over $1,000 per gram.

The relative anonymity of the material compared to gold etc may have appealed to the smugglers (although fossils are hardly anonymous). It's probably a better strategy than that used by the smugglers who carried 'heavy cheese' into Turkey last year.

• More news on Space
• Enjoy the read? Don't forget to sign up for your free newsletter with exclusive content