A Montgomery County jury will not be allowed to hear a tape recording of murder suspect Hadden Clark speaking with former prison inmates about 6-year-old Michele Dorr's 1986 disappearance because the recording violated Maryland wiretap laws, a judge ruled yesterday.

Clark, who is serving a 30-year sentence for the 1992 murder of a Bethesda woman, is scheduled to go on trial Sept. 27 on a first-degree murder charge in Michele's disappearance. Clark has pleaded not guilty.

The girl was last seen walking out of her father's Silver Spring home in May 1986 wearing a pink bathing suit with white polka dots and a ruffle to play in a backyard wading pool. She has never been found.

As part of their case against Clark, Montgomery prosecutors had planned to play a tape that two Maryland prison inmates, including Clark's former cellmate, recorded on a portable stereo hidden under a bed in their cell. The inmates testified in a recent court hearing that they had heard news accounts that Clark was considered a suspect in Michele's disappearance and that they made the tape hoping to use it as leverage in reducing their own sentences.

In seeking a warrant for Clark's arrest last fall, Montgomery police wrote that Clark had told fellow inmates that he had "murdered a little girl" while he was moving out of his brother's house.

Clark told the inmates that he found Michele in his niece's bedroom and cut her, then carried her body out in a duffel bag and put it in his truck, police wrote. Clark's brother lived next door to Michele's father, and Michele often played with Clark's niece.

Clark also told the inmates that he cleaned the floor of the little girl's blood before going to work, police wrote. A chemical test on the bedroom floorboards later revealed blood, police wrote.

It was unclear from charging documents whether the tape recording excluded by the court contained that information, and prosecutors declined yesterday to describe what Clark said on the tape.

Assistant State's Attorney James Trusty said the ruling by Montgomery Circuit Court Judge Paul H. Weinstein does not preclude prosecutors from calling the former inmates to testify at the trial. Usually, witnesses are only allowed to testify about what they saw, not about what other people told them. However, that rule doesn't apply to witnesses testifying about the defendant making an "admission" to them, Trusty said.

Still, Trusty said, "Obviously you want a jury to hear a tape of a conversation rather than take an inmate's word" about it.

Clark's lawyers argued that the recording violated Maryland law because Clark did not know he was being taped and that he had a "reasonable expectation of privacy." His lawyers could not be reached yesterday afternoon.

Prosecutors argued that the former inmates did not know they were breaking the wiretap law and that Clark should not have presumed the conversation was private because he knew he was in prison, where inmates and guards could easily overhear him.

Clark spoke to the inmates while in prison for killing Laura Houghteling, 23, of Bethesda, in 1992. Clark led police to Houghteling's shallow grave seven months after she disappeared and after he pleaded guilty to second-degree murder in her slaying. Her throat had been slashed.

If convicted in Michele Dorr's death, Clark would face a maximum sentence of life in prison without parole.