The committee is investigating whether the Senator improperly helped contributors win Federal contracts.
Mr. Magid contends that Mr. Guttman improperly helped force the liquidation of accounts.
In 1989 he resigned his port post amid allegations that he improperly helped an investment bank he worked for obtain a city hall contract.
Those shelters, which improperly helped wealthy investors and companies avoid paying billions of dollars in taxes, include two known as blips and cards.
The Senate Ethics Committee has been asked to investigate whether Senator Tom Daschle improperly helped a friend in trouble with air safety inspectors.
There have been allegations in the press, none yet proved, that he improperly helped financial institutions and investors with which he had personal dealings.
Prosecutors said he had illegally carried sidearms and improperly helped demolish a duplex he says was a crack house.
The Christian Coalition was cleared of improperly helping GOP candidates.
Mr. Rowland faces a federal corruption investigation and an impeachment inquiry, both of which center on whether he improperly helped steer state contracts to people who gave him gifts.
It was yet another case of corporate insiders improperly helping themselves to other people's money.