A three-month Virginia State Police investigation failed to uncover evidence that Del. David G. Brickley or his business associate, a Prince William County supervisor, improperly used inside information in their firm's land dealings near the proposed site of a new county government complex.

Prince William prosecutor Paul B. Ebert, who released a summary of the Virginia State Police investigative report, said he planned no further action. The report states that "no witness was located who had factual information" that Supervisor G. Richard Pfitzner, a leading county Democrat, gave Brickley inside information.

The state police also said Pfitzner passed a lie detector test, while Brickley declined to submit to a test. A polygraph examination of a third partner, real estate broker Virginia Hoy, "revealed deception as to her prior knowledge relating to the location of the administrative complex site," the report states.

Hoy said she failed the polygraph because she was upset at the time. She had just learned that her mother was ill, she said, and she was also about to lose her job because of the depressed real estate market.

All three partners in the company, B.H.P. Real Estate and Investment Corp., said Thursday they feel vindicated by the police investigation, which they requested after newspaper reports of the land deals.

"I'm very happy it's finally over," said Brickley, a delegate since 1976. "I think we went the extra mile on it."

Brickley said he gave the police investigators all the information they asked for but declined to submit to a polygraph examination. "I just felt I had some human dignity left," he said.

The investigation followed disclosures that B.H.P. helped broker the sale of a 16-acre property, negotiated for a 50-acre parcel and asked dozens of owners if they would sell their land near a site that Pfitzner and his colleagues on the county board were privately considering for the new complex.

The board in February chose a site in that eastern Prince William neighborhood, which real estate experts said would increase land values in the area. County officials are now working on plans to move their headquarters from Manassas.

Pfitzner and Brickley both said the supervisor had not been involved in the private land brokering, which was arranged by Brickley, and that the two officials never discussed where the county complex would go.

"Obviously, they've talked to everybody in the world and haven't come up with anything but rumor and innuendo," Pfitzner said. "I'm sure the world is pretty shocked that I'm an honest lawyer and an honest politician."

Brickley said he may suffer some political damage from the episode. "I think there will be some who won't be satisfied," the legislator said. He said he may not seek reelection this year, but his decision will not be affected by the county complex controversy.

Pfitzner also said he may not run again in 1983. "This really kind of puts you off your food," he said. "Would you rejoice or would you be embittered that you were investigated in the first place?"