The 55 local investors who were promised a 15 percent return on funds placed with National Investment & Retirement Accounts Inc. stand to lose all their money instead.

Last week a federal grand jury in the District indicted Joyce Gowie-Gamble, president of the K Street NW firm, on charges of mail fraud. Gowie-Gamble, who lives in suburban Springfield and also uses the name Derrell, has been involved with at least two other investment companies that went out of business.

The indictment said NIRA investors gave Gowie-Gamble a total of $260,000 to invest, but "almost all the client money was spent for corporate operating expenses and personal expenses of the defendant."

NIRA was supposed to invest in real estate, accounts receivable, limited partnerships, venture capital financing and other interest-earning businesses. In fact, the indictment charged, NIRA "never invested client funds in interest- or profit-generating vehicles."

Reached at her office before the indictment was handed down, Gowie-Gamble referred inquiries to her attorney for criminal matters, Raoul L. Carroll. He said he was no longer representing her, and she did not return a second phone call.

John F. Snyder, an attorney representing Gowie-Gamble on civil matters, declined to answer questions on facts in the case. He said his client's intentions were good, her ideas sound and she had no intention of defrauding investors.

The indictment charges that Gowie-Gamble "did knowingly devise and intend to devise a scheme and artifice to defraud and to directly and indirectly obtain money and other things of value by means of false and fraudulent pretenses, representations, promises and the concealment of material facts from individuals contracting with NIRA to be their investment manager." A felony conviction for mail fraud is punishable by a fine of up to $1,000 and/or five years in prison.

Clients, former employes, bankers, creditors and lawyers familiar with NIRA said Gowie-Gamble, 36, established the firm at 1511 K St. NW in June 1984. NIRA said it specialized in self-directed Individual Retirement Accounts described in promotional material as "comparable to regular savings and thrift activities," as well as other investments.

NIRA advertised "the 15 percent solution," saying in a newsletter dated this past March that, "NIRA is an exceptional blend of accepted investment principals [sic] from the banking and insurance industry. . . . NIRA earns a little less profit in order for the investor to earn a higher rate of return on dollars placed through NIRA."

Another document signed by Gowie-Gamble boasted, "The minimum of NIRA investment earnings is 30 percent . . . ." It went on to state that "we maintain 20 percent of each investment dollar under [a] reserve account and invest 80 percent to produce your guaranteed interest rate and operating expenses."

As for safety of principal, NIRA's disclosure statement declared, "All funds held in the custodian bank [United National Bank in the District]are [Federal Deposit Insurance Corp.] insured."

Gowie-Gamble also claimed in her newsletter that NIRA was affiliated with United National Bank, but bank officials said the firm was merely a customer. Paul Interdonato, United National's attorney, said that when the bank realized that it was being misrepresented, it advised Gowie-Gamble in January 1984 to "terminate the relationship immediately."

Interdonato said the bank was just a "passive custodian," charged with doing the paperwork on IRA accounts, but with no input into how the funds were invested. The customers signed a power-of-attorney document giving NIRA the authority to manage their funds as it saw fit. The money was all held in NIRA's name and Gamble wrote checks on the accounts, bank officials said.

The indictment charges that NIRA hid the fact that it was "virtually bankrupt" as of this past May. In March, Gowie-Gamble told the credit-rating service Dun & Bradstreet Inc. that NIRA's net worth was $25 million. Publicist Linda Bolliger said that last October she told D&B at Gowie-Gamble's request that NIRA had made a profit of $100,000 and had an investment portfolio worth $200,000.

NIRA's troubles surfaced, a former employe said, when some investors asked to withdraw their money and couldn't get it. Last week's indictment followed a grand jury investigation in which postal inspectors unsuccessfully sought to tape-record conversations between Gowie-Gamble and a disgruntled investor.

A Maryland woman, who discussed her role in the case on the condition she not be named, said she had invested $9,500 with NIRA and succeeded after many efforts in getting $2,250 of her investment back. After she complained to federal authorities, she said postal inspectors asked her to confront Gamble while wearing a concealed body microphone. The effort was a failure: Not only did the woman get no answers from Gamble about where the money went, but the equipment malfunctioned.

Former employe Diane Mullens of Waldorf said she not only invested $15,000 in NIRA but also went to work for the company. She said that when she tried to get her money out, Gowie-Gamble wrote a check, but then stopped payment.

Both women contend United National should be held responsible for the return of their money because it is listed as custodian on their IRS forms.

However, bank president Samuel Foggie replied, "I didn't even know those people [NIRA]. They had no authority to do that; they simply had checking accounts in NIRA's name."

NIRA was not registered with the Securities and Exchange Commission nor was Gowie-Gamble registered as a stockbroker in the District of Columbia.

A New York native, she claimed 14 years' financial experience in material she sent to clients. In October 1981, she established Advance Planning Personal and Business Financial Services Inc., a sole proprietorship she ran from her Alexandria home.

The following November she declared bankruptcy, citing $26,750 in debts and only $4,000 in personal assets, according to court documents. She had previously declared bankruptcy in Albany, N.Y., in 1975.

In 1983, Gowie-Gamble set up American Financial and Investment Services Inc., an Alexandria financial consulting and investment firm.

In addition to Gowie-Gamble, NIRA's board of directors consisted of three men and one woman. One director identified in the company's records was Richard L. Jones, an attorney in the enforcement division of the Commodity Futures Trading Commission. A CFTC spokeswoman said the agency's rules require employes to disclose outside work for which they are paid.

Jones denied that he received money from NIRA but declined to discuss his relationship with the company. The CFTC spokeswoman refused to comment on the matter or to say whether the agency knew of the criminal charges involving the company with which Jones was affiliated. The division in which Jones works is responsible for protecting investors from fraud.

Most of the money taken in by NIRA went to pay the firm's expenses, according to the indictment. Ferrari Computer Services in Falls Church has sued the firm and claims it is owed $9,000 on $22,000 worth of computer equipment.

The indictment states that this past April Gowie-Gamble wrote an NIRA check for $33,970 as a down payment on a house in Fairfax Station that she occupied. The sale was not completed, however, and Merrill Lynch Relocation Management Co. is suing her for $30,000.