Capitol police are investigating conflicting police accounts of a car accident involving a congressman on Capitol grounds late Tuesday night, officials said yesterday.

Police said a car driven by Rep. William D. Ford (D-Mich.) crashed into the rear of a parked car on Southwest Drive shortly after 11 p.m., then continued west for 30 yards before stopping near South Capitol Street and Independence Avenue SE.

According to Lt. Robert Howe of the Capitol police inspections and internal affairs section, who is investigating the incident, "there is conflicting information" from officers on the scene involving questions of whether the congressman was trying to leave the area and whether he might have been drinking.

In a telephone interview yesterday, Ford denied allegations of impropriety, saying he asked a male passenger in his car to summon police and that there was "no reason" for police to administer any sobriety tests. He said it was his understanding that the investigation had been concluded.

"I creased the fender of a parked car with the fender of my car," Ford said. ". . . The incident is no longer an incident because we exchanged information between the owner of the car and me and it's all been taken care of."

No charges have been filed against Ford.

Howe said the accident apparently occurred when "the congressman dropped his pipe into his lap. . . . He was reaching for that, looked down to grab it and at that time struck the other car."

Police said Officer Kevin Caulfield, who was patrolling the grounds, heard the crash and summoned other officers on his radio. Caulfield said he ran up a hill along Southwest Drive toward the scene as two other officers came running from the opposite direction.

Howe said one of the officers "approached Rep. Ford and asked him if he was going to do anything about the accident."

Two additional officers arrived and Ford stayed to exchange information with them and to meet the owner of the damaged parked car, a Capitol custodian, police said.

Caulfield said in an interview shortly after the accident that he and other officers saw the congressman's car driving away from the area and stopping for a red light nearby. He also said he "smelled alcohol" while three feet away from Ford.

Although Caulfield said he told his superiors of his observations, he said they were disregarded and he was told he was no longer needed at the scene.

According to Howe, the "collective observation" of the other two officers and their sergeant was that "none of the factors normally associated with a drunk driver was present," so no roadside motor skills, breathalizer or other sobriety tests were given.

Howe said Caulfield's remarks went unheeded because he is not trained to investigate such accidents and because he was not one of the two officers assigned to the case. However, Howe said, all officers involved would be interviewed to determine what took place and "whether the actions of the officers there were all in accordance with established procedures."

He said it was not certain yesterday whether the congressman would be questioned further.

Police said Ford was driving his own car, which suffered minor damage to the right front. The other car, a green Ford Torino, had a dent along the left rear fender and a blown left rear tire.

Capitol custodian Kenneth McLaughlin, owner of the other car, said he was on duty at the time and was brought to the scene by police. He said he was told by an officer there that the congressman "had dropped his pipe out the window of the car" just before the collision.

McLaughlin said the congressman offered to pay for the damage.