A U.S. judge dismissed lawsuits against Barclays PLC and four other banks by investors alleging a multiyear silver price-fixing conspiracy, Reuters reported.

The investors based their case on 350,000 pages of documents and 75 audio tapes, obtained after a $38 million settlement with Deutsche Bank AG. This included chat messages that offered "smoking gun" evidence of how the five banks broke the law without participating in the price fix, the investors said.

However, U.S. District Judge Valerie Caproni wrote that, "Though the [complaint] plausibly alleges that the fixing banks conspired to depress the Fix Price, it does not explain why the non-fixing banks, which are competitors and counterparties, would be in on the agreement." Her decision dismissed the cases against Barclays, Bank of America Corp., BNP Paribas SA, Standard Chartered PLC and UBS Group AG.

Caproni also dismissed a case alleging gold price fixing by UBS between 2004 and 2013, saying there was no "plausible link" between UBS' large trading position and alleged twice-daily meetings among Bank of Nova Scotia, Deutsche Bank, HSBC Holdings PLC, Barclays and Société Générale SA aimed at London gold market fixing.

The cases were being heard in the U.S. District Court for the Southern District of New York.