Police were dispatched to the Henry J. Kaiser Convention Center, near Oakland’s downtown, after a worker noticed what appeared to be a human body in a wall that was being deconstructed.

“We found remains best described as mummified,” Lt. Ray Kelly of the Alameda County Sheriff’s Office said. “The conditions in the walls were such that the body was preserved in good conditions.”

Police plan on obtaining fingerprints to determine who the person is, how they got there and how long they’ve been there, Kelly said.

“Any theory is possible,” he said. “It could be anything from someone who got in behind the wall and became trapped and died to someone put the person there. God only knows.”

The convention centre, named for the ship-building industrialist who later founded what became one of the nation’s largest health insurance companies, Kaiser Permanente, opened in 1914 and was shuttered nearly a century later.

A redevelopment project approved in 2015 is turning the site into a mixed-use performing arts venue.