Arab financier Adnan M. Khashoggi, who stayed out f the United States for the last two years to avoid being subpoenaed in connection with an investigation into $100 million in illegal corporate payoffs, returned to Washington recently for secret meetings with federal authorites.

Khashoggi met last week with officials of the Securities and Exchange Commission. The Washington Post has learned.

At least four federal agencies have been trying to question Khashoggi about illegal payments made by American business to get contracts in the Middle East and elsewhere.

Lockheed Corp. has reported it paid Khashoggi $106 million in commissions on sales of TriStar and C-130 planes to Saudi Arabia between 1970 and 1975. Khashoggi's company, called Triad has been linked to questionable payments and kickbacks made by Northrup Corp. Raytheom Ashland Oil and other U.S. firm.

One of things federal investigators are trying to find out is whether Khashoggi received the money, and if so, whether he kept the millions of dollars in under-the-table payments or passed them on to corrupt officials of foreign governments.

Federal investigators say that after fugitive financier Robert Vesco, Khashoggi is the man they most want to talk to.

No criminal charges have been filed against Khashoggi, but federal investigators in the Lockheed case more than two years ago obtained subpoenas requiring him to answer questions.

Once a frequent visitor to the United States - coming here to do business and to visit Nevada gambling casinos - the multi-millionaire Arab merchant stayed out of the country after he learned of the subpoenas.

But last week he came back. He sat down with SEC attorneys SEC and justice department sources said, but they refused to disclose the substance of the talks or to explain how they were able to get Khashoggi to meet with them.

Justice Department investigators did not participate in the talks with Khashoggi but one official there said, "we have our own plans for him."

Criminal fraid investigators at the Justice Department civil enforcement officials from the SEC and representatives of the Internal Revenue Service and U.S. Customs all have been investigating Khashoggi's activities.

Washington Attorney James Bierbower, who has represented Khashoggi on some matters, declined to comment on reports of the meeting.

One way federal investigators put pressure on Khashoggi to cooperate was to "blackball" has plan to form a Bank Holding Company in California.

Khashoggi owns 97 percents of security Bank of Walnut Creek, Cal., and had sought to expand his banking activities here.

His application was rejected by the Federal Reserve Board after the SEC and Justice Department stepped in "Mr. Khashoggi's unwillingness thus far to cooperate with United States law enforcement authorities is not in keeping with what the board regards as acceptable conduct for the management of a bank holding company," the board ruled this summer.

Blocking Khashoggi'd banking plans was "one of the few ways we could get a handle on him" a Justice Department investigator said at the time.

Federal Reserve sources said Khashoggi has so far made no attempt to renew his bid to start a bank holding company.