Harold J. Smith, the Los Angeles-based boxing promoter accused in a lawsuit by Wells Fargo National Bank of defrauding the bank of $21.3 million, is actually Ross Fields, a former American University student and the onetime owner and operator of a Washington-area discotheque, the U.S. attorney's office in Los Angeles said in federal court yesterday.

Smith, described in court by prosecutors as "a fugitive bad check and bunco artist," declared in the packed courtroom, "My true name is Ross Fields," then burst into tears.

He and his lawyers said he has been undergoing an identity crisis in which he has not lived up to his responsibilities in the last few years.

Assistant U.S. Attorney Dean Allison said Smith, the chairman of Muhammad Ali Professional Sports Inc. (MAPS), left the nation's capital deeply in debt during the early 1970s.

The disclosures were made at Smith's arraignment on a charge of falsifying passport information.

In the last few years, Smith has put together fights that brought some of the richest purses in the country and has gained a reputation for lavish spending on promotion and purses.

U.S. Magistrate Vennetta Tasasopulous ordered Smith held on $200,000 bail, $100,000 on the passport charge and $100,000 on North Carolina charges of forgery and false pretenses dating back to 1975. The passport charge involved the use of a false name -- Harold Smith -- on a passport application in 1975. Since that time, Fields has used the Smith alias, according to prosecutors.

The disclosures in Los Angeles followed broadcasts over radio station WOL here yesterday morning that Smith, 37, was actually Fields. Dewey Hughes, one of the owners of WOL, said he identified Fields from tapes of an interview Howard Cosell had with Smith that was broadcast on ABC-TV March 28.

American University officials said records confirm that Fields was a student there for three years, but that he left in 1966 without earning a degree. While at American University he was a middle-distance runner on the track team and ran on one of the nation's top mile relay teams.

After he left AU, Fields operated the Sammy Davis Jr. Discotheque at 13th and E Streets NW, and a music and fight promotions organization called Ross Fields Productions, both of which eventually folded. D.C. police records show 14 bad check charges pending against him in the late 1960s and early 1970s, but it was not known last night whether any of the charges were still pending.

On Feb. 1, Wells Fargo officials filed suit against Smith, his wife, several MAPS associates and a former bank official, charging they had conspired to divert funds from the bank over a period of two years, using a technique in which MAPS accounts were credited with deposits that were never made.

A few days earlier as reports of the fraud had begun to circulate, Smith, his wife and their 4-year-old son dropped out of sight and remained in hiding for two months. Later Smith told news organizations he had been pursued by men with guns, that the "Japanese mafia" had been threatening him and that he feared for his life. He was arrested Saturday by FBI agents on the passport falsification charge.

At the time of his disappearance, Smith admitted MAPS owed between $8 and $10 million to Wells Fargo, but he said the loans were legitimate. They would have been repaid, he said, from the proceeds of a boxing extravaganza scheduled for Feb. 23 at Madison Square Garden, which was to have purses totaling more than $8 million. That event was canceled after Smith's disappearance.

Prosecutors also said Smith's wife has been living under an assumed name. They said her true identity is Alice Vicky Darrow, a fugitive since 1975. She has been calling herself Barbara Newman Smith. She is wanted for interstate transportation of fraudulent securities and, Allison said, "has been an accomplice of Ross Fields in bunco schemes since the early 1970s."

The former Wells Fargo Bank official named in the suit is L. Benjamin Lewis, who is also a director of MAPS. He left his office for lunch on Jan. 26 and has not been seen since.

Although former heavyweight champion Muhammad Ali left his name to MAPS, he has played no part in the active management of the company, according to published accounts.

In the WOL broadcast yesterday, Rock Newman, a boxing consultant to the station, said Fields left the area in the early 1970s with "a tremendous debt liability to many people."

Hughes later said that he was one of those people. "He (Fields) borrowed money from me for some closed circuit fight concessions. They did not come through, and he said he would pay me back in installments, but the second check bounced and I never saw him after that," Hughes said.