A rap music star known popularly as "Just Ice" was held without bond on felony murder charges yesterday in connection with what prosecutors called a drug-related, execution-style murder last year at Howard University.

D.C. Superior Court Judge Shellie F. Bowers ordered the detention of Joseph Williams, 20, also known as "Just Ice," as well as his friend Donald J. Allen, 19, both of New York, after a government prosecutor argued that the two men fatally shot Ludlaw Desouza, a cocaine dealer, in the stomach Nov. 14, 1985, and then fled to New York.

"Latoya," Williams' first record, is played regularly on a number of radio stations and yesterday a spokesman for Fresh Record Company, Williams' recording label, called the single "an important record."

"It's a big one," said the spokesman, who declined to be named. One source said yesterday that more than 50,000 recordings of "Latoya" have been sold.

In urging her client's release yesterday at the bond hearing, Williams' lawyer Avis Buchanan told the judge "Mr. Williams' employer" is "very interested" in gaining the singer's release and was willing to post bond for him.

Rap music involves spoken verse, often improvised, and has become increasingly popular among youth.

Williams and Allen were arrested on March 25 in New York and extradited here. Prosecutor William Martin told the judge yesterday that the two men were arrested after an informant told police that Allen, Williams and Desouza were in a Howard University dormitory room when the informant was told to leave the area. A short time later, the informant told police, Williams told him that he and Allen had "shot and killed" Desouza.

Martin said Desouza was not a Howard student but sold cocaine at the dormitory. Martin said the informant and Allen also were involved in a "cocaine ring," but that Williams was not.

Martin said Desouza's body was later found in the alley of the 100 block of W Street NW, where police believe others may have placed it.

Yesterday a lawyer who represented Williams at the extradition hearing in New York called the government's case "preposterous."

"It is our firm belief that he will be totally vindicated," said attorney Irving Cohen. He called Williams' arrest a "tragic mistake," and said his confinement would seriously impair Williams' budding career.