Joseph Nesline, a well-known Washington gambler who says he is "retired," was jailed here today after refusing to answer questions before a federal grand jury investigating bribery allegations involving U.S. District Judge Alcee Hastings of Miami.

Despite being given immunity against future prosecution, Nesline refused to testify because his attorneys contended he is taking medication that could impair his memory.

U.S. District Judge Sidney Aronovitz said the medical reasons were not sufficient and found Nesline in contempt-of-court. Nesline, 68, was taken to the Federal Correctional Institute here.

Judge Aronovitz ordered Nesline incarcerated until he agrees to testify. Otherwise, he must remain in jail either until the grand jury term expires next September or for 18 months, the maximum permitted by statute.

Federal prosecutors did not indicate why they want to question Nesline. But his Miami lawyer Neal Lewis said he understood the questions involve a government informant, William C. Dredge, who allegedly said he was told by Washington lawyer William A. Borders that Hastings was interested in soliciting payoffs from accused criminals who appeared in his court.

The grand jury probe began shortly after Oct. 9, when Borders, a friend of Hastings, was arrested in Arlington, Va., and accused of accepting a bribe from an undercover FBI agent on Hastings' behalf.

The immunity granted to Nesline is the first sought by federal prosecutors during the four and one-half month investigation of Hastings.

During his first appearance before the grand jury Wednesday, Nesline invoked the Fifth Amendment. Then the government requested and Aronovitz granted immunity to Nesline. Still Nesline refused to testify.

At that point, the judge allowed Nesline's attorney to study overnight the government's motion to find Nesline in civil contempt. "Tell your client to bring his toothbrush," Aronovitz advised Lewis as he scheduled today's hearing.

In court today, Lewis said he had spoken Wednesday night with Nesline's personal physician, Dr. Herbert M. Wechsler in Washington. Lewis produced Nesline's prescription bottles for Dilantin, an anti-convulsant, and phenobarbital and Tuinal, which are used as sedatives or anti-hypnotics, depending on the dosage. Lewis said he was told that Nesline suffers "seizures and convulsions."

Nesline's physician could not be reached.

Judge Aronovitz cited Nesline for contempt and allowed him to undergo physical examinations during detention. The judge said Nesline's attorneys may request a hearing when they believe they have substantial evidence to support his medical claim.

Nesline's arrest record goes back four decades. It includes gambling charges as well as bribery and bootlegging arrests and one conviction for carrying a deadly weapon. Last May, Nesline was placed on probation for five years and fined $10,000 after he pleaded guilty to one count of income tax evasion in U.S. District Court in Washington. He was also ordered to perform 400 hours of community service work.