The suitcase was originally left in a station locker, but after no-one returned to claim it, it was taken to left luggage and opened by staff.
"There was an abnormal odour when we opened the suitcase. Then we saw hair," an unnamed employee told reporters.
The victim was a woman aged between 70 and 90 and about 140cm (4ft 7ins) tall.
She had been folded into a yellow suitcase measuring about 70cm by 50cm by 25cm.
Police were also examining security camera footage to try to determine who left the case behind.
The locker company employee said the suitcase was not in the locker on the morning of April 25 — the day before it was found — narrowing the timeline for its placement.