BALSAM LAKE, Wis. — The body of a missing western Wisconsin toddler was found in the trunk of a car near his home, just hours after authorities called off an exhaustive all-day search of the surrounding property that drew more than 2,000 volunteers.

Two-year-old Isaiah Theis disappeared Tuesday night. About 10:15 p.m. Wednesday, after a day of blistering heat, a Polk County sheriff's deputy found his body in the trunk of a locked vehicle near Isaiah's home near Centuria. Searchers had looked into the car and checked the area around it several times, Sheriff Peter Johnson said in a statement.

Isaiah's maternal grandfather, Paul Krey, told KARE-TV (http://kare11.tv/18ni2Ql ) that the car belongs to a customer of his son-in-law, who is an auto mechanic and works out of a shop on his property. Krey said the car was parked there and waiting to be fixed. All the Theis children were comfortable hanging around the shop and spent plenty of time around the vehicles while their father worked, the grandfather said.

"Searchers had been advised that the vehicle had been locked prior to Isaiah being reported as missing and that it was extremely unlikely that he could have been in it based on that information," the sheriff's statement said.

After the owner of the car arrived to remove it about 10 p.m. Wednesday, a deputy opened the trunk and found the boy's body.

"A full autopsy has been requested and it would be inappropriate for anyone to speculate as to the cause and nature of death until that examination has been done," the statement said.

Johnson didn't immediately return a call seeking more details.

The boy's mother told investigators Isaiah was last seen about 7:30 p.m. Tuesday while playing with his 5-year-old brother at their home near Centuria, which is about 60 miles northeast of St. Paul, Minn.

About 2,450 civilian volunteers helped search the fields and woods surrounding the family's home throughout the day Wednesday, the sheriff said.