An Idaho boy who vanished from his home Monday night during his fifth birthday party has been found dead, police say. 

Matthew Glynn, who was nonverbal and had autism, was discovered "deceased in the water" of a canal about half a mile away from his home, according to the Boise Police Department. 

"It is heartbreaking to have such a conclusion to this effort when we had so hoped to find Matthew alive and well," Boise Police Chief Ron Winegar told reporters Tuesday. 

"The investigation is ongoing and at this point there appears to be no signs of foul play," the Boise Police Department added in a statement. 

TEXAS FAMILY MISSING ON ALASKA VACATION AFTER BOAT CAPSIZES OFF COAST 

Police say the search for Glynn began Monday night after he disappeared from his home around 5:45 p.m. local time. 

"A large search effort was launched by Boise Police, Boise Fire, and Idaho Mountain Search and Rescue," Boise Police said, noting that it involved drones, K9s and utility task vehicles. "Detectives with the Ada County Child Abduction Response Team also began an investigation and officers searched door to door in the area where he went missing." 

Idaho Mountain Search and Rescue spokesperson Scotty Perkins told KTVB that searchers played Glynn’s favorite song, "Wheels on the Bus," in hopes that it would attract his attention. 

"When you have an autistic subject that's nonverbal, they tend to exhibit preferences and behaviors that are potentially a little bit more predictable," he told the station. "So, we employed some of those strategies that we had been given."  

MISSING HIKERS IN YOSEMITE NATIONAL PARK FOUND ALIVE AFTER 2-DAY SEARCH 

Boise Fire Chief Mark Niemeyer said in a statement that "this is not the outcome we were all hoping for. 

"Our hearts go out to Matthew's family, and we extend our deepest condolences during this incredibly difficult time," he added. 

Boise Police say the body that was found is presumed to be him and the "Ada County Coroner’s Office will make an official identification."