The United States is reportedly probing major banks over possible manipulation of precious metals markets.
The investigation centres on prices for gold, silver, platinum and palladium, the Wall Street Journal says.
It is being carried out by the Justice Department with help from Commodity Futures Trading Commission, which regulates raw materials and derivatives, the newspaper said, quoting sources close to the case.
The banks targeted are HSBC, Bank of Nova Scotia, Barclays, Credit Suisse, Deutsche Bank, Goldman Sachs, JP Morgan, Societe Generale, Standard Bank and UBS.
The probes are at the preliminary stage, but HSBC, in releasing yearly results on Monday, noted requests from the Justice Department and the CFTC over the precious metals probe, the Journal said.
It is not the first time the role of banks in determining the price of precious metals has been questioned, but the probes carried out so far, mainly in Europe, led nowhere, the paper said.
Goldman Sachs, HSBC, Standard Bank of South Africa and the German chemical group BASF have also been under investigation since November over a complaint alleging rigging of the prices of platinum and palladium.