Italy’s antitrust authority launched an investigation yesterday into seven companies suspected of passing off lower-quality olive oil as the extra virgin variety prized for its rich flavour and health benefits.

Tests by police this week suggested oil sold as extra virgin by some of Italy’s best-known brands may not meet strict labelling requirements, the authority said in a statement.

The probe comes after prosecutors in the northern city of Turin investigated the same companies on suspicion of commercial fraud and false labelling to deceive consumers.

The probe follows a nightmarish year for Italian producers

Being put under investigation does not imply guilt and does not necessarily lead to charges, but the accusations are a blow to an industry that prides itself on quality. Italy, the world’s second largest producer of olive oil after Spain, exports hundreds of thousands of litres a year, contributing to an overall turnover that agriculture group Coldiretti estimates at €2 billion. The Agriculture Ministry has demanded clarity to protect consumers and producers.

Three of the brands under investigation are owned by Spanish olive oil giant Deoleo, which said its extra virgin variety passed scientific and taste tests in Italy. Deoleo, which owns the Bertolli, Carapelli and Sasso brands, said it would ask Italian authorities to make counterchecks. Renato Calabrese, director-general of the Pietro Coricelli brand, which is also in investigators’ cross-hairs, rejected the allegations and questioned the science behind them.

The objection is based on a taste test, not chemical or physical analysis,” he told Reuters, adding that his company ensured its oil was subject to the latter kind of assessment.

The probe follows a nightmarish year for Italian olive oil producers, in which groves endured bad weather, a fruit-fly blight and a bacterial disease dubbed”olive tree leprosy”.

But trade associations say the outlook is better this year. Italian groups Assitol and Federolio say the global harvest currently under way should yield 22 per cent more than last year, and Italy should see an almost 60 per cent increase.