The Tokyo Metropolitan Police said the corpse was found Sunday in a suitcase in a temporary storage area at Tokyo’s main train station.
Japanese media reports said the body was of an elderly woman, 140 centimeters tall (4-feet, 7-inches) tall. Police are trying to establish her identity.
“There was an abnormal odour when we opened the suitcase. Then we saw hair,” an unnamed employee told reporters.
The bright yellow suitcase was left in an unlocked coin locker on April 26, according to the media reports. It measured 70 by 50 by 25 centimeters (28 by 20 by 10 inches).
Nothing unusual was observed about the suitcase, no odor or anything, said Junichi Omoto, a spokesman for regional train company JR East.
“We were surprised and horrified,” he said.
It’s normal practice to hold abandoned luggage for a month to see if anyone claims it.
Major Japanese train stations have banks of lockers for travelers to store items temporarily.
Tokyo station is one of the busiest in Japan, handling about 150 million passengers a year, JR East said.