When Maryland Gov. Marvin Mandel got into a financial bind three years ago as a result of his divorce, some of his friends bailed him out. Now that he is on trial in federal court charged with corruption linked in part to these gifts, his friends are being asked again to help pay the governor's way.

There was a lull in contributions to Mandel's legal defense fund following the declaration of a mistrial last Dec. 7, according to fund trustee, Hotsy Alperstein. But with the second trial "the money has started to flow again. It's amazing," he said.

They are assured, at least for the moment, a measure of secrecy in their contributions not accorded to a public official's benefactors since before the advent of campaign finance disclosure laws. Their names are not being made public. The amount they contribute is unlimited by law.

And because the money is placed in a blind trust (even Mandel is not supposed to know who gives) the governor apparently does not have to disclose the funds on his personal financial disclosure format.

There are no contribution restrictions for people who do business or are regulated by the state and cash is accepted.

Although the money in the fund is a closely guarded secret, J. Carson Dowell of Cumberland, one of three trustees of the fund, indicated that 800 to 1,000 persons have contributed as much as $200.000.

Dowell said no one has contributed more than $3,000 because of internal Revenue Service complications but that several have given that amount. "Yes, indeed, the governor's got some real boosters," he said.

Even so, Dowell admits that the fund has not been able to keep up with the "astronomical" legal bills (some place the figure near $500,000) resulting from the necessity of Mandel's having to stand trial a second time. "Lawyers don't give you two trials for the price of one," noted Konstantine (Gus) Prevas, the fund's counsel.

Arnold M. Weiner, the governor's chief criminal lawyer, sends Dowell an itemized bill, listing hours and expenses, each month. Weiner won't discuss his fee, but legal sources said a top-flight criminal attorney such as Weiner may charge $100 an hour or more.

"We're behind," Dowell said. "We still owe him money from the first trial. Dowell said he has told Weiner "When I have it, you'll get it."

The trustees insist that they have no obligation to make public details of the fund, despite a 1974 state law that requires public officials to file an annual statement reporting each gift in excess of $50, its nature and value, and the identity of the donor.

"We've checked it all out," said Dowell, and determined that the law does not apply to the defense fund.

State Sen. Julian L. Lapides (D-Baltimore), the principal sponsor of the legislation, said such interpreta tions "point up a glaring loophole in our financial disclosure laws." He said he "hopes to correct the omission" in next year's session of the General Assembly.

Lapides, a political foe of Mandel, noted that the 1974 law was proposed in the wake of disclosure of repeated payoffs to Maryland politicians, and that Mandel and his codefendants were indicated subsequent to its passage.

In a declaration of purpose, the statute said "people have a right to be assured that the financial interests of holders of --- oublic office present no conflict with the public trust."

Backers of the Mandel Defense Fund offer a similar statement, however, in arguing that the fund should be secret.

Prevas, a Baltimore lawyer who serves as legal counsel to the trustees, said the names of donors are not revealed so that Mandel, who is on leave as governor does not know who is contributing.

"Lacking such knowledge, it can't be said that it (the fund) in any way influenced his judgment with regard to his public duties," Prevas said.

In his 1976 financial disclosure report, filed with the Maryland secretary of state on April 15. Mandel wrote that the "purpose of the fund was to provide a fund for payment of legal fees and other costs and expenses incurred in the preparation and presentation of my defense to certain charges pending in U.S. District Court."

Under terms of the agreement, Mandel said he "waived any right to an accounting by the trustees as to receipts and disbursements. I therefore do not know, and have no ability to discover, what contributions have been made to the fund, who has made such contributions" or what happens to the money after it is received.

While Alperstein said the fund raisins has been handled "in a very quiet, low key way," there have been several bursts of publicity about it.

The Annapolis lobbyist for the archdiocese of Baltimore was chastised by the archbishop after The Washington Post reported that he was soliciting money for the fund. The Baltimore Evening Sun reported that Ellis Duke, a fund raiser, was soliciting money from nursing home operators while he was vice chairman of the state board that regulates nursing homes.

Duke, whose tenure on the board expired last month, said that even if he had wanted to influence actions of the regulatory board, he could not because only four of its nine members are from the nursing home industry.

Another flap resulted from a $20-a-person bull roast held at the Kent Island Yacht Club on May 15 by "friends of Gov. Marvin Mandel." Although sponsors of the event said Mandel would be given free rein to use the profits as he saw fit, chairman James (Joy) White III, a Republican attorney from Chestertown, said it was "likely" that the proceeds would go to the defense fund.

Edward W. Lupinek, one of the promoters of the event, earlier this month announced that Mandel would be given about $3,500 from the proceeds to use "for whatever he wants." But when that announcement raised some eyebrows, Lupinek, a seafood dealer from Chester, backed off the statement, saying last week that no decision had been made about what to do with the profits.

Prevas, who is the personal lawyer of the third trustee, Baltimore baking company owner John Paterakis, said that guidelines called for contributions to "generally conform to good taste standards. . . Trustees are expected to use conservative discretion about whom to accept money from. For example, not from notorious criminals or from firms whose contributions would raise eyebrows. . ."

Alperstein's own firm, which sells playground and athletic equipment, does a "minimal amount of business with the state." He said his major clients are county governments parks departments and school boards." Powell said he reached to his friend's indictment with disbelief. He called Mandel and said "this is not right. I know you're not guilty."

He volunteered to head the fund because he resented that "my federal tax dollars are being used to prosecute him. So, damn it, some other of my dollars are fighting it."

Dowell expects that contributions to the fund will step up as soon as Mandel gets his chance to testify, to tell his side of the story.

"And if he'sexonerated," Dowell beamed, "we'll have a fund raiser at the Baltimore Civic Center and pay off all the debts in one night."