The Renewable Fuels Association (RFA) is urging the Commodity Futures Trading Commission (CFTC) and the Environmental Protection Agency (EPA) to investigate possible manipulation in the US market for biofuels credits.

In a letter on 1 August, the RFA said it was concerned about “recent irregular activity and volatility” in the market for Renewable Identification Number credits (RINs), which it said had climbed about 30% since May.

“The recent spike in RIN prices appears contrived and driven by something other than basic supply-demand fundamentals”, the RFA said.

A RIN is a serial number assigned to a batch of biofuel to track its production, use, and trading as required by the US Renewable Fuel Standard. RINs can be sold and traded separately from the biofuels that created them, giving rise to instances of RIN fraud, where improperly created RINs have been sold without any manufacture of corresponding biofuels.

In March, the CFTC and the EPA signed an agreement regarding RINs in which the CFTC agreed to help the EPA investigate possible fraud and market abuse of RINs, Reuters said.