Patrick James Knowlton, who lives just eight blocks from the White House, alleged there was "a conspiracy to obstruct justice" with regard to the investigation of Foster's death.
Knowlton was driving home from his job at a construction site in Maryland when he got caught in traffic and had to stop at the park to urinate.
"He was there for five minutes and he saw some things that later turned out to be very significant which refutes [sic] the theory that Vincent Foster committed suicide in Fort Marcy Park," says John Clarke, a Washington lawyer who represents Knowlton.
Knowlton, who says he was followed and harassed by "no fewer than 25 men," is asking $1.5 million in damages in the sealed suit, filed last month in federal court in Washington. It is expected to be unsealed today.
The suit also names FBI agents Lawrence Monroe and Russel Bransford as defendants. Attorney General Janet Reno will be served with the complaint by the end of the week.
Knowlton says he arrived at the Foster death scene at around 4:30 p.m. on July 20, 1993. He said he was soon interviewed by agent Monroe, who he claims has since falsified a statement he gave.
Knowlton says the FBI changed his testimony about the type of car he saw in the park, what was in the car and information about a "Middle Eastern or Hispanic looking man" he saw in a blue-grey sedan in the parking lot.
When he was shown a copy of the FBI report in October 1995, Knowlton said the document contained "outright lies," says Clarke.
For instance, Clarke says the report claims Knowlton identified a Honda with Arkansas plates in the parking lot of Fort Marcy Park. The car was parked in the same space where Foster's car was later found.
Knowlton claims in the suit that he saw a different older car of another color in the spot in which Foster's vehicle was later found.
On Oct. 22, 1995, an article was printed in the London Sunday Telegraph that contained Knowlton's allegations.
Two days later, the FBI prepared a subpoena for Knowlton to appear before the Whitewater grand jury in Washington.
The subpoena was served on Knowlton on Oct. 26.
Knowlton says on that day "began an orchestrated campaign of intimidation and harassment perpetrated by at least 25 men, who followed him on the street while giving him a lock-eyed, fierce constant stare. Back to back, one after another," Clarke says.
Clarke says there are witnesses to these harassments and photographs of some of the men bothering Knowlton.
Clarke says his client passed a polygraph exam given by a former chief polygraph examiner for the FBI.
(John Crudele is a financial columnist with the New York Post. His mailing address is P.O. Box 610, Lincroft, N.J. 07738. Click here to send him e-mail).