ROME - Italian police on Thursday seized assets worth 163 million euros ($207 million) in a nationwide operation against alleged illegal gold trading activities, local media reported.

According to investigators, the illegal activities were coordinated by a Swiss-based criminal organization which was operating in various regions across Italy.

Police blocked 500 bank accounts, and carried out 259 raids in houses and cash-for-gold shops linked to the ring, which had allegedly dealt in 4,500 kilograms of gold and 11,000 kilograms of silver only during the last year.

Dealings reportedly took place on the black market through a network of unofficial gold traders in exchange for high denomination banknotes, police said.

A total number of 118 people were put under investigation in the Mediterranean country with charges of criminal association, money laundering and reinvestment of illicit income, receipt of stolen goods, illegal gold trading and tax fraud.