BOSTON (AP) _ The right of attorney-client privilege is being tested in the Stuart murder case as prosecutors try to pry information from the lawyer for the man who apparently killed himself after he became a suspect.

Prosecutors trying to unravel Charles Stuart's alleged plot to kill his pregnant wife asked a judge Thursday to lift the privilege that has silenced Stuart's former attorney.

The courts have ruled both ways in previous cases in which lawyers have been asked to disclose what they were told in confidence, legal experts said.

''There's always going to be a temptation that this is an important case and you need that information,'' said William J. Genego, a law professor at Boston University.

Suffolk Superior Court Judge James Donohue took the case under advisement after the hearing Thursday, which was closed because of a grand jury investigation.

The motion centers on a conversation Stuart had with his attorney, John Dawley, before he died on Jan. 4.

Dawley has refused to reveal the details, but it is believed Stuart disclosed his role in the Oct. 23 shooting death of his pregnant wife, Carol.

Paul Leary, an assistant district attorney, said his office was asking the court to allow prosecutors to get information from Dawley.

''We will pursue every avenue to get to the truth,'' Leary said. ''This may be one of them.''

Another key witness in the case is Stuart's younger brother, Matthew, who provided the dramatic revelations that led to Charles Stuart's suicide.

Prior to January, authorities believed Stuart's tale that he and his wife were attacked by a mugger. But Matthew told police that his brother instructed him to be at the murder scene, where Charles gave him some of his wife's belongings and a revolver.

Matthew Stuart was called before the grand jury last week, but he reportedly refused to testify to avoid self-incrimination. His attorney, Nancy Gertner, attended Thursday's court hearing, representing the Stuart estate.

''We believe the attorney-client privilege extends past death, period,'' Gertner said.

Deborah Ramirez, a visiting law professor at Northeastern University, said judges can order an attorney to disclose privileged information from a dead client. But some courts have ruled in the other direction, she said.

''If I were a judge, I would find a way to order that the privilege not apply,'' she said. ''But I think I'm in the minority.''

Legal experts disagree over whether the power to waive the privilege can transfer to the client's heirs. In this case, Stuart's mother is the administrator of his estate. Her attorney, Richard Clayman, said, ''even if she can waive it, she won't waive it.''