Food fans are told to prepare for a flood of dangerous counterfeit olive oil

A senior Italian food fraud investigator told The Independent that he has already seen evidence that criminals are moving into olive oil production and distribution

Olive prices have doubled recently as a poor harvest means output has fallen to its lowest level in 15 years (Timothy Allen)

British shoppers have been warned to beware of counterfeit olive oil – as criminal gangs exploit a disastrous Italian harvest by selling potentially dangerous bootleg bottles.

A senior Italian food fraud investigator told The Independent that he has already seen evidence that criminals are moving into olive oil production and distribution.

Consumers should be particularly wary of olive oil that appears “too cheap to be true”, experts said. Fake oil produced in unhygienic conditions could put Britons at increased risk of E.coli and salmonella.

The incentive for fraud has increased because the woeful olive harvest has left a shortage of the fruit required to make genuine oil – while the resulting rising price has increased the profits that can be made from selling fake bottles.

Consumers should be wary of 'too' cheap oil (AFP/Getty) (AFP/Getty Images)

“Organised criminals are going into it rapidly. We estimate that there will be an increase in criminal interest in this field,” the Italian investigator said.

He said it was likely that some of the counterfeit product could end up in the UK, which is a big consumer of Italian olive oil. The Italian and British authorities are in discussions about how best to tackle the threat, he added.

“The criminals have international links and are able to shift this product overseas where other criminals will supply it. There are some networks that are able to supply Italian restaurants overseas, so there is a threat from that,” he said.

Olive oil prices have doubled in recent weeks as output tumbled by nearly a third to its lowest level in 15 years. Italy’s pre-eminent growing region, Puglia, was hit particularly hard after millions of olive trees were infected with a deadly microbe.

In one type of the fraud, the counterfeit olive oil is relatively harmless, although it is illegal and dupes the consumer out of their cash. In these cases, “Italian extra virgin olive oil” is produced using older, inferior oils from other countries and passed off as a fresh, top-of-the-range product from Italy.

But another version of the fraud poses a far greater risk. In this case, vegetable oil is presented as olive oil by blending it with chlorophyll – for colour – and beta-carotene for flavour.

The rising cost of olives could push up oil prices (AFP/Getty) (AFP/Getty Images)

This poses a danger for people with allergies to chlorophyll – who can develop symptoms such as chest pains and rashes. There is also a risk from the poor hygiene standards employed by the bootleggers, the Italian investigator warns. “It’s not just a question of sub-standard products; it’s a question of health and safety. They do not respect hygiene requirements for food production. They often work in garages and the basements of houses, so it is not a clean place and you can get bacteria contamination,” he said.

The best way for consumers and restaurant buyers to determine whether olive oil is counterfeit is to look at the price. Olive oil comes in so many different varieties and qualities of pressings that it is difficult to compare prices, but broadly it has varied from about £4 to £6.50 a litre at the supermarkets over the past two years.

Experts predict that the rising cost of olives will push up the price of olive oil by about a quarter once it has fed through into the retail system – making any litre bottle of olive oil for much less than £5 look suspicious.

Eoghan Daly, of the Institute of Food Safety Integrity and Protection, said: “They could be mixing in a farm building where they could be introducing E.coli and salmonella risks into the olive oil through cross-contamination. Or in an industrial place, where there could be all sorts of hazardous chemicals.

“And there could be physical contamination through foreign objects such as bits of glass.”

He stressed he was outlining a worst-case scenario.

“The UK is a significant consumer of olive oil with a supply chain running directly from Italy to the UK. It’s a reality that this is happening,” added Mr Daly.

He said the counterfeit product is much more likely to find its way into Britain’s catering and restaurant trade and small, local shops than the big retailers.

Mr Daly is keen for the fraudsters to be found and punished as soon as possible. “If they get away with it, maybe it will be mineral oil rather than vegetable oil they use next time,” he warned.

Know your olives: Facts about the fruit

* Olive trees and oil production can be traced back to the ancient Syrian city-state of Ebla in around 2400BC.

* About 70 per cent of the world’s olives are grown in Spain and Italy. Greece, Portugal, Morocco and Tunisia produce most of the rest.

* The harvest in Puglia, southern Italy has been hit hardest in this year’s bad crop, down by more than 40 per cent.

* Olive oil is produced by pressing whole olives and is used in cooking, cosmetics, pharmaceuticals and soaps.

* The oil is rich in vitamins and energy and regarded by many as the healthiest of the edible oils. It is used across the world as a dressing, for frying, on bread and in baking.

* Extra virgin olive oil is the purest form. It’s made by purely mechanical means. It is the only cooking oil made without chemicals and industrial refining.

* Olive oil started appearing in British kitchens in the 1970s when people adopted parts of the Mediterranean diet.