(IDEX Online) - Four Canadian men have been charged at a court in Ohio, USA, with a pink diamond and jewelry investment fraud following an FBI probe.They are alleged to have cold-called potential investors in the US and Canada and persuaded them to make small investments in pink diamonds, which, they claimed, would increase in value. The defendants claimed to work for Paragon International Wealth Management, Inc., a Canadian investment firm that sold investors diamonds and other jewelry items, according to court documents cited by the US Attorney's Office for the Norther District of Ohio.They are alleged to have run a number of fraudulent schemes. They are accused of encouraging investors to pay extra for larger diamonds investors that they could sell to a wealthy international buyer. They allegedly asking investors to give Paragon more money in order to "upgrade" their diamonds and make them more valuable at fabricated diamond auctions.And they are accused of sending customers fraudulent appraisal certificates, which inflated the value of an investor's diamonds they purportedly owned.Named in the charging documents are James Gagliardini, 44, of Unionville, Ontario; Michael Shumak, 52, of Markham, Ontario; Anthony Palazzolo, 64, of Pickering, Ontario and Jack Kronis, 63, of Toronto, Ontario. They are each charged with one count of wire fraud.