Maine State Police say an investigation has cast doubt on parts of a report made by the driver of a tanker truck who told troopers he was shot at and robbed on Interstate 95 in Howland on Tuesday evening.

In a news release issued Wednesday, state police had said that the driver of the truck hauling water for Poland Spring reported being shot at by occupants of a red car and then, after pulling over on the highway, being pulled out of the truck by men in the car and getting robbed. The truck driver was not injured during the alleged robbery.

On Thursday, state police said they have doubts about aspects of the truck driver’s story.

“After collecting physical evidence, digital evidence, and conducting follow-up interviews, troopers have determined that the alleged shooting of a tractor-trailer by a passing motorist and subsequent robbery did not occur as it was reported,” Stephen McCausland, spokesman for the Maine Department of Public Safety, said in a news release. “At this point, investigators have concluded that there was no attempt to target the truck or the company, and that there is no ongoing risk to the public.”

A shot was fired, but “it did not happen in the way that it was reported to us by the driver,” McCausland said.

The driver of the truck, who has not been identified, has not been charged. McCausland declined to say whether charges would be filed.

“We are still trying to determine the back story,” he said. “The story that he gave us on the night of the incident did not take place as he reported it. Now, we are trying to figure out why.”

McCausland said the water tanker was carrying water from Poland Spring’s plant in Lincoln, but the company does not own the truck and it was not marked with its name or logo.

State police had asked for the public’s help in finding the occupants of the red car that the truck driver said fired at his rig while both vehicles were traveling south on I-95 near the Mattamiscontis/Howland town line.