CLARIFICATION The General Services Administration National Capital Federal Credit Union is the institution at which a $733,000 embezzlement was uncovered last fall. The complete name was not included in a Metro story yesterday.

Two former officials of the General Services Administration Credit Union's L'Enfant Plaza branch who pleaded guilty to embezzling more than $700,000 have been sentenced to stiff prison terms by a federal judge who said he doesn't believe they have told investigators where all the money went.

"You have violated the public trust . . . for your personal gain," U.S. District Judge Louis F. Oberdorfer said yesterday as he sentenced Rosa Marie Lewis, 30, of 2720 Loring Dr., Forestville, the credit union's former loan officer, to serve at least three years in prison.

On Tuesday, Oberdorfer sentenced the credit union's former head cashier, Evelyn Frye, 42, of 2016 D St. NE, to at least four years and eight months in prison. But he told both women he would consider reducing their sentences if they were more candid about what happened to the money.

Both women have failed lie detector tests about what was done with the money.

Investigators have discovered that Frye purchased a Cadillac, a customized van and a motorcycle for herself and several dump trucks for her boyfriend and had made numerous trips to Atlantic City, N.J., to gamble. They also have found that Frye and Lewis visited Hawaii.

But Assistant U.S. Attorney Eric Marcy said the money has been hard to trace because most the $733,000 taken from the credit union was in cash.

Including lost interest, legal fees and auditing costs, he said, the total loss to the credit union and its insurance company was $860,000, the largest ever sustained by a District credit union and the third largest in the country.

"They ran the credit union like their own personal little cash drawer," Marcy said.

Oberdorfer ordered Lewis to repay $440,000 and Frye to repay $402,000. A third person who participated in the embezzlement scheme, former acting credit union manager Floretta Roye, 15129 Alaska Rd., Woodbridge, also pleaded guilty and was sentenced to 36 months' probation. She must repay $24,000.

According to court documents and testimony, Lewis conceived the plan shortly after she went to work for the credit union in December 1982. The first withdrawals were made in October 1983.

Frye testified that Lewis persuaded her to take part in the scheme, which involved about 80 loans to fictitious persons, and they agreed to split the money 50-50.

Although interest was computed on the fictitious loans, few payments were made and most of the loans were carried on the books as inactive. The scheme was uncovered last fall during an independent audit of the credit union.