Police arrested eight people Tuesday linked to a defunct Tokyo-based commodity futures trading firm on suspicion that they swindled three company executives out of about 135 million yen, officials said.

Metropolitan Police Department officials said the arrests may be only the tip of a wider futures trading scam that may have bilked as many as 800 investors out of some 9.5 billion yen.

Yoshio Yokoyama, 39, who effectively ran a futures trading firm called Core Creation, which collapsed last April, allegedly worked with seven others to persuade the executives into investing in soybean futures and other commodities on the Chicago Mercantile Exchange from July 1994 to December 1997.