A man's "badly decomposed" body was found early Thursday in a storm drain on the southbound 605 Freeway in Lakewood.
Detectives did not immediately suspect foul play in the man's death, according to the Sheriff's Department statement.
Television news footage showed law enforcement officials using a tripod to lower someone down into the storm drain to retrieve the body.
The freeway's northbound and southbound carpool lanes were temporarily closed from Carson Street to Centralia Street as detectives investigated the scene.
Anyone with details about the body was asked to call the Sheriff's Department's Homicide Bureau at (323) 890-5500.