The collection of around 100 silver coins, thought to date from the 12th century, were found in a grave dating from the early 14th century.
"Graves from that time are so often empty. That bags of money are buried together with the body is totally unique."
Menander and her colleagues, Annika Konsmar and Magnus Stibéus, concluded that the coins must have been in circulation over a very long time.
The hidden treasure was found when the area was being excavated to prepare for new train tracks to link Mjölby and Motala. Excavations were conducted at the site five years ago, but were then ended only centimetres from were the coins have now been found.