Police have named the boy who died after a log fell on him in Timaru at his father's workplace as Felyx Rhys Hatherley, from Pleasant Point.

The boy died at Point Lumber in Washdyke after a log rolled onto him about 3pm yesterday, an employee named Mike confirmed.

He said the investigation was ongoing and didn't comment further.

Detective Senior Sergeant Richard Quested, of Timaru, said the boy's father was at the site on Sunday afternoon doing a job, Fairfax reported.

"He's just devastated.

"His son was his whole world and now he's not there. He's absolutely distraught."

The preschooler was rushed to hospital by family when they were met by a police car, Fairfax reported.

An officer then took the boy to hospital in the police car. The boy later died of his injuries.

Police said Felyx's family had asked for privacy at this time.