BERLIN (AFP) - Germany has launched a probe into suspected potato price fixing over the past decade which may have cost consumers and farmers hundreds of millions of euros, local media reported on Saturday.

The national competition regulator is investigating allegations that at least nine production and distribution plants illegally agreed on prices for deliveries to grocery chains as well as those paid to farmers, press reports said.

The Suddeutsche Zeitung said the profits notched up by those involved in the alleged cartel - dubbed the "Kartoffel Kartel" by the press - could amount to hundreds of millions of euros.

Bild newspaper said investigators had raided the premises of the nine companies and that another five risked fines for links with the cartel, suggesting the illicit gains could run up to one billion euros.

But the manager of one of the businesses targeted denied there was a cartel, adding: "We have absolutely no guilty conscience."