The futures trading industry reeled on Tuesday as federal regulators accused Iowa-based broker PFGBest with misusing over $200 million in customer funds for more than two years, resurrecting the shock of MF Global's collapse.

The Commodity Futures Trading Commission (CFTC), which had give a clean bill of health to the brokerage industry in January, said that the broker's regulated Peregrine Financial Group (PFG) unit and its owner had failed to maintain sufficient capital in segregated accounts since at least February 2010.

It said the shortfall was in excess of $200 million, more than half of the broker's total client funds.

"The whereabouts of the funds is currently unknown," the CFTC said in a complaint against the regulated broker arm and Russell R. Wasendorf Sr., the founder and chairman of PFGBest whose apparent suicide attempt on Monday morning outside the firm's Cedar Falls, Iowa, offices appears to have triggered the crisis.