The CFTC said it continues to look into allegations of market manipulation in the silver market from August 2008 when prices fell, but an acting director of surveillance at the agency proposed possible reasons why it may have happened.

In written testimony at the CFTC's hearing about possible position limits on the metals futures markets, Steve Sherrod, acting director of surveillance at the CFTC's division of market oversight noted when Comex silver prices fell sharply there was no magnitude change in the aggregate long or short positions in the commitment of traders' positions in the agency's weekly data. Nor was there a significant change in open interest during the period of July and August 2008. These are some of the reasons critics claim manipulation.

"One could explain a change in short open interest on the BPR (bank participation report) by a change within the classification system; if the usage code changed from non-bank to bank for a trader with a short position, then an increase in the short open interest would appear on the BPR, without any change in the COT (commitment of traders) Report.

"Another explanation would be a merger or acquisition where a bank assumes the position of a non-bank entity, both of whom were under the same commercial classification. That may not result in a change in open interest and may not result in a change in aggregate position within a COT classification. But it may result in an increase in the reported position on the BPR," he wrote.

Officially the CFTC has said it has nothing to report yet on its investigation of the silver market action.

Sherrod also said generally the commission does allow publication of "data and information that would separately disclose the business transactions or market positions of any person and trade secrets or names of customers. So, I can do no more than offer these alternative explanations."