(IDEX Online) - Five banks and two diamond brokers in Italy are alleged to have made $590m by selling clients gems for investment at vastly-inflated prices, according to a Reuters report.Four of the banks - Banco BPM, Banca Aletti, UniCredit and Monte dei Paschi (MPS) - and one broker - IDB - are facing possible prosecution over the alleged fraudulent diamond sales, together with over 100 former employees who are accused of fraud and bribery. The Intesa Sanpaolo bank and the diamond broker DPI are reported to have reached settlements and paid modest fines to avoid a possible trial.Documents issued by the Milan-based prosecutors indicate that the allegedly fraudulent diamond sales ended in 2016, after which all the banks started reimbursing clients and many began buying back diamonds at the original selling price.A judge must now decide whether trials are to take place. Reuters said it had not received responses from any of the named banks or brokers.