The figure at the center of Wall Street's latest insider-trading scandal also played a key role in another drama: the daring 1979 rescue of two American hostages held in Iran that was financed and orchestrated by H. Ross Perot.

Reza Saleh, a longtime employee of Mr. Perot's businesses who has lived quietly in Texas for 30 years, was accused by federal regulators Wednesday of making $8.6 million in illicit profits from Dell Inc.'s proposed purchase of Perot Systems Corp.

But...