Federal prison officials dismissed charges of drinking while on furlough yesterday that had been lodged against Marvin Mandel when he returned this week to the Florida prison camp where he is serving a three-year term.

Officials at the Eglin Air Force Base prison found that the "balloon test" used to determine that Mandel had been drinking was improperly

Upon his return to Eglin late Wednesday after a five-day furlough in Maryland, the former governor was placed in detention when he failed the balloon test. Inmates on furlough are prohibited from drinking, officials said. Mandel remained for one night in the detention cell from his dormitory cubicle.

The incident created a furor when Mandel's wife Jeanne called reporters Wednesday night, saying that prison officials were punishing her husband for having given press interviews during his stay in Annapolis. Prison officials denied her contention, saying the test is "standardized" and given to all returning inmates.

Bereano said Mandel checked prison regulations and found that officials should have allowed him to wash out his mouth and wait 15 minutes before they gave him the balloon test.

Mandel pointed this out at a disciplinary hearing held yesterday at the prison, Bereano said. The disciplinary committee also concluded through its own research that there had been this "administrative error," according to a prison source.

The charge, which could have affected Mandel's chance at future furloughs and resulted in other sanctions, was dismissed and erased from his record, the source said.

A Maryland State Police expert on alcohol testing devices said this week the balloon test is "unreliable" and that substances other than alcohol, for instance, tobacco smoke, can cause the test to register positive.

Bereano said Mandel had been smoking his pipe when he returned to Eglin Wednesday.

Mandel has served 14 months of his sentence for political corruption, and is scheduled to be paroled next May.