Loudoun County Sheriff Donald L. Lacy, who is being investigated by Virginia officials on allegations of misconduct and possible criminal activity, has announced that he will step aside from his office during the inquiry, but that he will not resign.

The 34-year-old Republican denied any wrongdoing and said he would relinquish his duties to sheriff's Capt. Albert Keyes during the investigation. Lacy also said he has resigned his position as cochairman on the committee to elect Republican Kenneth Rollins to the House of Delegates.

The accusations against Lacy have been sealed by order of Circuit Court Judge Carlton Penn, who selected Richmond Commonwealth's Attorney Aubrey Davis as a special prosecutor. Davis has been directed to investigate "allegations of misfeasance, nonfeasance, malfeasance or criminal activity" involving Lacy.

Penn took his action after Loudoun's chief prosecutor Thomas D. Horne sent him a letter detailing the allegations against the sheriff. Horne disqualified himself from the investigation because of his working relationship with Lacy. He also refused to divulge the specific allegations against Lacy.

One county official, who asked not to be identified, said the allegations involve misuse of sheriff's employes, charges that Lacy often fails to show up for work and charges concerning Lacy's personal life.

In a press conference Tuesday evening, Lacy called the rumors "malicious." His attorney, John Moorcones, said the allegations "are the foulest rumors I have ever heard about a politician. I've gone through some foul campaigns, but these are just extremely malicious rumors and they're not true."

Moorcones served as Lacy's campaign manager two years ago when he upset Loudoun Sheriff Robert Legard, a veteran of 16 years. Lacy, who lives in the eastern end of Loudoun where the population is dense and suburban, charged during the campaign that Legard was still running the department in a rural, small-town way. Two years earlier, a special Loudoun County grand jury had found the administration of the county sheriff's department to be "inadequate and inefficient."

"This whole thing is a shock to me, to my family and I want the investigation to continue so it can clear me and my family," Lacy said at a news conference in Moorcones' office. "Two years ago everything was fine and dandy and now, all of a sudden, the ship's going down."