A special grand jury has been called in Prince William County to investigate allegations of criminal activity by state officials, brought by a man who was convicted in March 1983 of raping and sodomizing a 23-year-old Annandale woman.

Kenneth L. Titcomb, 31, charges that several officials conspired to withhold evidence and convict him unfairly in his trial three years ago. In a telephone interview yesterday from the state corrections unit in Haymarket, where he is imprisoned, Titcomb said that on March 18 he appeared before a Prince William County Circuit Court grand jury and gave them "evidence that showed criminal activity in state officials in deceiving the court and jury and contriving my conviction."

After hearing Titcomb's testimony, the grand jury voted unanimously to appoint a special grand jury to investigate the allegations, according to court records.

Titcomb said he has evidence that "several state officials" were involved in an attempt to undermine his defense, but declined to be more specific, saying that it could jeopardize the special grand jury's investigation.

"I can easily prove the suppression of exculpatory evidence by the Commonwealth Attorney, tampering and altering official police reports, use of testimony known to be perjured," he said in a letter last October to Circuit Court Judge H. Selwyn Smith. The letter, on file at the Prince William Circuit Court, does not detail the allegations.

"I really don't know what the allegations are," said Prince William Commonwealth Attorney Paul B. Ebert. "My suspicions are that they involve things that have been litigated several times."

Titcomb's case received publicity three years ago when, five days before his scheduled sentencing, he tricked authorities into believing that he had killed himself by parking his van on the Chesapeake Bay Bridge with a suicide note inside. Three months later, he walked into the Prince William courthouse and surrendered.

Prince William prosecutors charged in the trial that Titcomb, who operated a Rockville towing company, abducted at gunpoint a woman whose car had broken down on the Capital Beltway, drove her to a secluded spot near the Quantico Marine Corps base in Prince William, then raped and sodomized her.

Titcomb maintained his innocence throughout the case and twice has attempted to have his conviction overturned.

Titcomb said he testified before the special grand jury Monday, the first day that it convened, and is to testify again on April 24.

Grand jury proceedings are closed to the public. Robert Bendall, a Manassas attorney appointed special counsel to the jury, declined to comment yesterday.

If the special grand jury recommends the prosecution of any officials, a regular grand jury would be appointed to weigh the evidence in the case and decide if criminal indictments are warranted.