The acting chairman of the Montgomery County Ethics Commission discussed a confidential investigation despite strictures in county law against such an action, telling at least three persons that the commission's inquiry was designed to "get" County Council member Esther P. Gelman, according to a council report released yesterday.

The council's Office of Legislative Oversight was ordered to examine the ethics commission's handling of the investigation in October after Gelman and Paul H. Sterling Jr., chief of the Wheaton Rescue Squad, charged that the probe was a politically motivated effort to harass them.

The probe was dropped last month for lack of a sworn complaint and evidence of wrongdoing.

Andrew Mansinne Jr., who directs the office, said yesterday in an interview that the county ethics law clearly forbids breaches of confidentiality by members of the ethics commission.

In a sworn statement, acting ethics chairman Harold W. Needham denied discussing the investigation. But the report, citing "a preponderance of evidence," concluded that Needham discussed the case with Sterling, who was a subject of the investigation, and with two persons not involved in the case, Candace S. Schimming of Silver Spring and Charles Hubush of Rockville. Hubush and Schimming were meeting with Needham to discuss working together in a political campaign when the conversations took place, according to sworn statements by the two that were noted in the report.

"Mr. Needham told us that he told Paul Sterling not to worry about it, that the investigation wasn't about 'you guys'; the investigation was to get Esther Gelman," Hubush said in his sworn statement, alluding to an October meeting he and Schimming had with Needham.

Yesterday, Needham declined to comment except to say that he may consider withdrawing his nomination for reappointment to the commission. His two-year term expired in October; he was renominated by County Executive Charles W. Gilchrist.

County Council President Michael Gudis said yesterday that the council will turn over copies of the report to Gilchrist and to State's Attorney Andrew L. Sonner.

Violating the county ethics law is a misdemeanor punishable by up to a $1,000 fine, a year in jail or both. Any decision to prosecute would be made by the state's attorney, Gudis said.

The report concluded that the commission launched the investigation without a sworn complaint, but it suggested that the action was the result of "errors" in judgment and confusion over the law among commission members. It did not address whether the probe was politically motivated.

The investigation began in April after the commission received a written inquiry questioning the propriety of efforts by Gelman and 14 members of the county's Fire and Rescue Association to defeat questions on the 1984 election ballot that would have changed the way council members are elected from at large to councilmanic districts.

The identity of the person who made the inquiry has been kept confidential by the commission, but yesterday, in an interview with The Washington Post, council member Rose Crenca acknowledged that she had made the inquiry.

Crenca is considered one of Gilchrist's allies on the council, while Gelman is considered a Gilchrist antagonist. Crenca and Gelman ran on opposing slates in the 1982 election.

Crenca said yesterday, "I never accused anybody, I only asked a question. I have kept more than an arm's length with the ethics commission. I cannot see how this could possibly have been politically motivated. Until now, Mr. Gilchrist or his staff knew nothing of this stuff."