Seven of Italy's best-known olive oil companies are being investigated for allegedly conning consumers by passing off inferior quality olive oil as extra-virgin.
Extra-virgin oil costs, on average, about a third more than ordinary oil and is typically green-gold in colour. It is made by crushing the olives soon after they are picked and involves no chemicals or industrial refining.
Ordinary olive oil has a higher acidity and is produced with the aid of heat or chemicals. It is lighter in colour and has less flavour.
The alleged fraud was first discovered by an Italian consumer magazine in May and then investigated by the authorities. They announced this week that of 20 brands tested in the laboratory by specialists from the Italian customs agency, nine were found to be lower quality oil.
The producers caught up in the investigation include Bertolli, Santa Sabina, Primadonna and Antica Badia. The other three leading brands are Carapelli, Coricelli and Sasso.