One of Japan’s most popular zoos has delayed its reopening after an employee reportedly told police he had burned his wife’s body in an incinerator on its grounds.

Asahiyama Zoo in Hokkaido’s second-largest city of Asahikawa, which had been closed for a seasonal break since April 8, was set to reopen on Wednesday, a national holiday. But the date has been pushed back to at least Friday to allow police to search for the body, according to The Asahi Shimbun newspaper.

At a news conference on...