WESTPORT — A Weston man’s body has been recovered from the Aspetuck River near Easton Road and Bayberry Lane, after his vehicle sank behind Aspetuck Falls in Fairfield apparently during torrential rainfall Sunday night.

The body of 59-year-old Robert Macisaac was found shortly before 5:30 p.m. Thursday in a local stretch of the river by a search-and-recovery operation led by Fairfield police, who first were notified five hours earlier about the submerged vehicle.

Officers from the Westport police marine unit assisted Fairfield police in the operation, according to Lt. Eric Woods.

After the initial report, a Fairfield police diver confirmed the submerged vehicle was unoccupied. Investigators then learned the vehicle was last seen about 10 p.m. Sunday in Wilton, and a broader search-and-recovery operation was launched, according to the report. The operation, in addition to involving Fairfield and Westport police, was assisted by Weston police and State Police aviation and K-9 units.

Macisaac’s body was located early Thursday evening in a section of the river not far from the intersection of Easton Road and Bayberry Lane, Fairfield police said. The official cause of death will be determined by the state’s chief medical examiner.

Although the accident investigation continued Friday, preliminary findings indicate that Macisaac’s vehicle left the road and plunged into the river because of “severe weather conditions that occurred in the area this past Sunday,” according to the report by Fairfield police.