Several Washington area real estate firms, mortgage companies and appraisers will be dropped from federal housing programs this week because of their alleged roles in widespread mortgage loan frauds, officials of the U.S. Department of Housing and Urban Development said yesterday.

"We're going forward with debarments," said Janet Hale, acting commissioner of the Federal Housing Administration, employing the technical term used when a person or company is barred from business with the FHA's parent agency, HUD. "It's unusual for the Justice Department to authorize us to go ahead before there are indictments."

Justice Department officials would not comment about why the agency was granted approval. In Camden, N.J., and Milwaukee, two cities where similar mortgage fraud investigations have recently been completed, those indicted were later barred from participating in federal housing programs.

Paul Adams, inspector general of HUD, said 148 persons or firms were barred from federal housing programs last year.

The U.S. attorney's office, the local office of the FBI and HUD's inspector general are investigating several hundred home loans in the Washington area in which applicants may have falsely stated they paid the necessary down payments on properties. Indictments of up to 25 people are expected in several months, according to one source familiar with the investigation.

Similar investigations are under way in Houston, Seattle, Atlanta and Nashville and have turned up millions of dollars in fraudulently obtained loans for which the government is now liable.

The schemes generally work like this: False appraisals are made, boosting the value of the property. Sham owners, who never occupy the property, default on the payments and the federal government reimburses the mortgage company for the inflated value of the property.

"It's not a nationwide ring, where someone in Washington is directing the scam in Atlanta," said Hale. "The same kinds of fraudulent activity" crop up in several cities, she said, because those familiar with federal loan and insurance practices learn how to abuse the system.

In the District, officials said, the swindles involve at least 250 properties in low-income neighborhoods.

In some cases, according to Hale, the names of sham purchasers or "straw buyers" were used to win mortgage loans, which the federal agency insured. When no mortgage payments were made, the loan would default and the federal government become liable for the mortgage amount.

Others involved innocent mortgage applicants who were misled by dishonest real estate or settlement agents seeking fees. They were led to believe their finances could support a mortgage, Hale said.

One group of mortgage applicants were members of a District church "who got the information in a church basement," she said. "Some of these people were set up unwittingly."

In court documents filed last year, the Justice Department estimated losses in the Washington area at $5 million, involving 250 properties. Hale said it cannot be determined if losses will exceed that figure until HUD attempts to resell the foreclosed properties.

"We get a big percentage of the money back if they go into default," she said, adding that the government refuses to reimburse mortgage firms whose applications are found to be fraudulent. She said HUD has no figures on the number of claims it has rejected because it discovered fraud in the application process.

According to FBI affidavits filed last year, two Prince George's County mortgage companies, Guaranty Mortgage Corp. of Greenbelt, and Marathon Mortgage Corp. of Suitland and Lanham, supplied all of the questionable loans under investigation by federal authorities.

Guaranty Mortgage Corp. is now a "skeleton" operation consisting of two employes, according to Nat Lewin, an attorney for Robert Becker, president of the firm. "It has complied with all the requests from the U.S. attorney for records for various loans," Lewin said.

Becker said, "Nothing was condoned or recognized as being improperly initiated" at his mortgage company's offices.

Allen Hossick, the Greenbelt office manager, said many of the questionable loans involved loan applications taken by phone, rather than applicants appearing in person as FHA rules require. One of the office's employes, Donna Johnson, was named in court records as approving several of the loans generated by by Spicer Real Estate Inc., a D.C. firm. Her husband, Fred Johnson, is sales manager of the Spicer firm. The firm's president, Jack Spicer of Potomac, declined comment. Fred Johnson could not be reached.

Henry Schuelke, an attorney for Donna Johnson, said, "She was a loan officer in connection with a number of loans. She categorically denies any wrongdoing whatsoever." He said she is now a loan officer with United Security Mortgages, a California firm that took over Guaranty Mortgage's four locations last fall and hired most of its employes.

Bob Herrera, president of Imperial Bankcorp of Huntington Beach, Calif., parent company of United Security Mortgages, said he asked HUD "to prove to me if any one of these people employes are phony. To this day, they've told me nothing." He said the four offices "are so clean, you could eat off the floor."

Officials of Marathon Mortgage Corp. could not be reached for comment. According to FBI records, one-third of 225 FHA mortgages the firm issued in 1983-84 were in default.