The man was fired last July after it was discovered that more than 1,800 items were missing.
According to the museum’s lawyers, the man has abused his position of trust to steal old precious stones, gold jewelry and other objects. The thefts are said to have been going on for a decade.
A judge has ordered the former employee to list or return the items in his possession. In addition, he must show his transactions on Ebay and Paypal.
The British Museum has so far been able to recover 356 objects and hopes to find more.
“The objects that have been stolen from the museum are of cultural and historical importance,” said the museum’s lawyer Daniel Burgess in the lawsuit.
According to Burgess, the former employee has tried to cover his tracks by, among other things, using false names and falsifying documents. He also allegedly changed the museum’s register.
The man is said to have sold items to at least 45 buyers around the world, according to BBC.
The designated man denies all allegations.
A police investigation into the events is ongoing in parallel with the civil case and so far the man has not been charged with any crime.