The UK’s Financial Conduct Authority (FCA) is investigating benchmarks used in the gold market as part of a probe of how global rates are set.

The FCA is conducting a preliminary investigation and hasn’t risen to the level of a formal investigation, reported Bloomberg.

The US derivatives regulator has cited reviewing how gold benchmarks are set earlier this year at a private meeting of the Commodity Futures Trading Commission.

The main benchmark in gold markets is the London gold fixing, which determines the spot price for physical gold and is set twice a day by a panel of five banks including Barclays, Bank of Nova Scotia, Deutsche Bank AG , HSBC Holdings and Societe Generale.

The probe has also fired reviews to improve how rates are set to prevent them from being rigged in the future.

The gold benchmarks follow the LIBOR-fixing scandal, where a number of key banks were investigated and fined for manipulating the interbank lending rate.