A brother of convicted drug dealer Rayful Edmond III refused yesterday to testify at the murder trial of Edmond associate Columbus Daniels, telling a federal judge that he had received an "intimidating" call from Daniels.

Robert Stewart, the only member of Edmond's immediate family who was not charged in a wide-ranging drug conspiracy case, was a witness to the June 23, 1988, slaying of drug dealer Brandon Terrell outside the Chapter III nightclub in Southeast Washington. Stewart had been expected to join four other witnesses in identifying Daniels as the gunman.

Instead, Assistant U.S. Attorney David Schertler told the court that two more witnesses have reported verbal threats sent by Daniels through two intermediaries, convicted Edmond associates James Antonio Jones and Harry Sullivan Jr.

Schertler also disclosed that notes discussing the threats and witness list were recovered Thursday night during a search of the D.C. jail cell of inmate Joseph Sweat, who Schertler said is being held on murder charges stemming from another drug conspiracy case. Schertler, referring to the Edmond drug gang, told U.S. District Judge Charles R. Richey that "this conspiracy is still alive and well, even if operating behind bars."

The prosecution asked Richey to admit evidence of the threats in Daniels's murder case. Richey denied Schertler's request, but said he did not want to "discourage" prosecutors from pursuing possible obstruction of justice charges against anyone involved in the threats.

Sources said the threats were made after the prosecution's witness list, in a routine pretrial move, was turned over to Daniels's defense attorney. Arthur M. Levin, Daniels's attorney, said he had no comment on the threat allegations.

Stewart, who is in jail on unrelated drug charges, had been scheduled to testify Thursday, but spent much of the day meeting with a court-appointed attorney in discussions about the threats. He told Richey of his decision not to testify while members of the jury were out of the courtroom.

The jurors' identities are being kept secret during the proceeding, as in the two previous drug conspiracy trials involving Edmond gang members.

Other witnesses who reported threats included Mattie Johnson, Terrell's girlfriend, who testified Thursday, and Theodore "Fat Boy" Smith.

A threat against Smith was the subject of the notes recovered from Sweat's cell.

The notes were to Sweat from "Antonio," who said that "Nut showed me his witness list" and asked Sweat to contact "Fat Boy" in Cell 61, the number of Smith's cell, Schertler said in court.

Sources said that Johnson was contacted at home and told "not to testify" by Harry Sullivan Jr., who originally was charged as a juvenile in the Edmond drug conspiracy case, but subsequently was charged as an adult.

He pleaded guilty to drug charges.

Schertler said in court that the threats against Smith were the reason Smith had given a private investigator working for Daniels a statement that he did not know who had killed Terrell.

That was contrary to Smith's grand jury testimony identifying Daniels as the gunman.

Schertler said that if an inmate tells others about plans to testify against someone, "you might as well be signing your own death warrant."