It is praised for its culinary and health properties by any cook worth his salt, but long before olive oil made it into the Mediterranean diet Cypriots used it as fuel to melt copper, archaeologists say.

Italian researchers have discovered that environmentally friendly olive oil was used in furnaces at a site in southern Cyprus up to 4,000 years ago, instead of the fume-belching charcoal used in industry for hundreds of years since.

Described as "liquid gold" by the ancient Greek poet Homer, olive oil has long been associated with grooming, pampering and the religious rites of the ancients, but not - at least in the Mediterranean - with heavy industry.