A grand jury in Prince William County refused yesterday to issue an indictment after investigating charges that state officials withheld evidence and misled the court in the case of a convicted rapist.

Kenneth L. Titcomb, 31, who was convicted in 1983 of raping and sodomizing a 23-year-old Annandale woman, had accused several officials of conspiring to withhold evidence and convict him unfairly. Titcomb is serving a 15-year sentence at a minimum-security state corrections unit in Haymarket.

By declining to indict any state officials in the case, the grand jury in effect exonerated the officials, according to Prince William Commonwealth's Attorney Paul B. Ebert. "In the absence of new information," said Ebert, "it's a dead issue."

A special grand jury was convened in April to investigate the charges. Its findings, although never made public, were passed to a regular grand jury.

Although the subsequent grand jury proceedings were secret and the allegations were never detailed, Titcomb had said he had evidence against "several state officials" involved in an attempt to undermine his defense. "I can easily prove the suppression of exculpatory evidence by [Ebert], tampering and altering official police reports, use of testimony known to be perjured," he said in a letter to Circuit Court Judge H. Selwyn Smith.

After the grand jury adjourned yesterday, Ebert said, "I'm not at all surprised. I think it's a waste of time . . . . More and more prisoners seem to feel like they can air their grievances before a grand jury with much more success than they can before a court of law. It puts a prosecutor in a bad position because you become the accused instead of the accuser."

Ebert is under a separate investigation by federal and state authorities for allegations that he twice received sexual favors in exchange for lenient treatment of a woman convicted of selling drugs in the county.

Titcomb's case was the subject of several news reports three years ago when he tricked authorities into believing that he had killed himself by parking his van on the Chesapeake Bay Bridge and leaving a suicide note inside, five days before he was to be sentenced. Three months later, he walked into the Prince William courthouse and surrendered.

Robert Bendall, a Manassas attorney who was appointed special counsel to the special grand jury, could not be reached for comment yesterday. He has declined to comment on the case in the past.