AUGUSTA, Maine — A bicyclist who died Friday while participating in the Trek Across Maine lost control of his bike while drinking from a water bottle as a tractor-trailer passed him, according to police.

David LeClair, 23, of Watertown, Mass., hit his head in the fall from his bike and he was partially run over by the big rig, investigators said. The incident occurred on U.S. Route 2 in the Oxford County town of Hanover.

“Based on witness statements, LeClair was sipping water from a water bottle at the time of the crash,” Lt. Walter Grzyb, commander of Maine State Police Troop B, which covers Hanover, said Monday. “Witnesses said when the truck went past, LeClair lost control of his bike and fell into the path of the truck.”

LeClair was pedaling with half a dozen of his athenahealth cycling teammates when the group was passed about 8:45 a.m. Friday by Michel Masse-Defresne, 24, of Quebec, who was carrying corn to Augusta for Transport Beauregard Inc., also of Quebec. Videos collected from a Rumford business and a responding police cruiser, and descriptions given by eyewitnesses, link the big rig to the fatality, Grzyb said.

LeClair had one hand on his handlebars as he drank from the water bottle, the lieutenant said.

“There was a draft created [as the truck passed] and it caused him to lose his balance and he fell over,” Grzyb said.

He was killed instantly.

LeClair’s group was about 10 miles into the trek. There was 3½-4 feet of separation as the truck passed the cyclists, who were riding in a group, possibly two or three abreast, they told investigators.

The medical examiner was sent to the scene, Grzyb said.

“What they concluded was that his arm was probably run over by the truck and he died as a result of blunt force trauma to his head,” Grzyb said. “He could have hit his head on a tire, or mud flap or the ground.”

Masse-Defresne was stopped by police a short time later in Rumford about six miles from the scene. The truck driver said he passed hundreds of bikes and “did not notice anything,” Stephen McCausland, spokesman for the Department of Public Safety, said Saturday.

There is little likelihood any charges will be lodged against the trucker, but the final crash report will be reviewed by the Oxford County district attorney’s office once it is completed, sometime in the next month or so, McCausland stated in a press release issued Monday.

Masse-Defresne has no infractions on his driving record in Maine and there was no issue with his truck, McCausland said Saturday.

The Trek Across Maine is a three-day, 180-mile bicycle ride that raises funds for the American Lung Association. It started at Sunday River ski resort in Newry and ended in Belfast. More than 2,000 cyclists participated.

LeClair graduated magna cum laude from Bentley University of Waltham, Mass., in 2011 and he started working for athenahealth in December 2011.

Around 130 of his fellow athenahealth team members wore red ribbons tied around their arms in his memory as they crossed the finish line on Sunday.