When questions were raised about suspected violations of campaign financing laws by Carter media adviser Gerald Rafshoon last year, he was investigated by the Federal Election Commission, the Justice Department and the Internal Revenue Service.

He was cleared. But his legal bill was "at least $100,000," he said, not counting staff time his advertising agency put into working on the case.

White House chief of staff Hamilton Jordan has been accused of snorting cocaine, an allegation that would not rate more than passing interest from law enforcement officers if he were a private citizen. He is now under investigation by a special prosecutor and has reportedly told friends his legal fees have passed $100,000 -- and the case is far from being over.

White House adviser Richard Harden was investigated for 18 months about allegations that he was involved in an alleged bribery attempt by fugitive financier Robert Vesco. The U.S. attorney's office here recently announced it was closing that investigation without any charges being brought. Harden reportedly paid about $100,000 in legal fees to his defense attorneys.

Carter supporter and friend Smith Bagley was investigated and tried on an unusual theory of stock manipulation last year, and was acquitted quickly by a jury without calling a single witness on his behalf. He has said publicly that he paid "hundreds of thousands of dollars" in legal fees, and has privately told associates the figure surpassed $300,000.

Former Carter budget director Bert Lance is still on trial in Georgia. His legal fees had passed the $500,000 mark before his 14-week trial began, and are expected to top $1 million.

These members of the Carter administration have encountered what appears to be a growing problem for persons either accepting political jobs or visibly attaching themselves to an incumbent administration: The high cost of legal fees in a post-Watergate climate requiring intense investigations of public figures.

Some of those who have been in the defense camps of administration figures under investigation blame the Justice Department and the press for the increased legal expenses.

"There is a reluctance on the part of certain persons in the Justice Department to make hard decision [to drop a case] when you have highly publicized cases regarding public figures," said Robert W. Altman, who represented Harden -- a White House administrative officer -- and has represented Lance.

Altman attributes that alleged reluctance to "fears of what the media will say," and said it is reflected in long investigations of otherwise routine allegations.

"Everyone is afraid of being accused of a cover-up," said another defense figure in one of the White House cases, who asked not to be identified. He cited the Jordan investigation as the most serious example of the problem. h

In that case, even Justice Department officials have expressed concern over the requirement that a special prosecutor be appointed. U.S. Attorney General Benjamin R. Civiletti said at the time that he was recommending appointment of the special prosecutor under the 1978 Ethics in Government Act only because of the strict standards that law imposes for weighing allegations against high-ranking government officials.

Civiletti said that in his judgment, a preliminary FBI investigation of the cocaine-sniffing allegations left it "so unsubstantiated that prosecution is not warranted." The law, however, requires appointment of a special prosecutor unless the attorney general concludes that the matter "is so unsubstantiated that it warrants no further investigation."

One attorney who has worked on cases involving highly visible public officials said such persons tend to turn to highly qualified, prominent and expensive lawyers when they are in trouble, and that such attorneys tend to spend unusually large amounts of time on the cases, at their usual rates of $100 per hour and more.

"One part of representing a public official is that you put more time on that than you would similar cases. You're double-checking everything," the attorney said . He noted that Jordan has retained former Watergate special prosecutor Henry Ruth Jr. and incoming D.C. Bar president Stephen Pollak to represent him on the cocaine allegations.

Justice Department officials said they did not want to discuss any of the specific cases against White House officials, but denied allegations that they prolonged investigations of public officials unnecessarily.

On the other hand, said one Justice Department official who has been directly involved in two of the investigations, "You obviously are careful to cross every 't' and dot every 'i'. You don't want someone to turn around and investigate you and claim you didn't do a good job of investigating a criminal allegation against a politician."

The Justice Department official also noted that high legal fees are a problem for anyone undergoing a criminal investigation -- whether that person is a private citizen or a public figure.

"But it's obviously a huge problem for a public figure who is not independently wealthy," said the Justice Department aide.

In a financial disclosure report filed last year, Jordan reported a negative net worth. It is unclear where he will get the funds to pay his massive legal bills if his attorneys ultimately hold him accountable for the whole amount.

Harden was unavailable yesterday to say how he intends to pay his legal bill, and Altman refused to discuss the matter.

Bagley is independently wealthy. Lance's considerable legal tab may be picked up by one of the banks he previously headed, The Post reported yesterday. Rafshoon is self-employed, and paid his bills himself.

However the legal bills of the individuals are paid, Carter administration figures have been complaining bitterly to acquaintances about what one attorney calls "endless investigations of ludicrous allegations."

"It's a high price to pay for public service," the attorney added.