After 21 years tucked away inside a Rotterdam flat, a priceless 18th century crown is finally being repatriated to Ethiopia with the help of a Dutch art detective.

For more than two decades, the crown has been guarded by Dutch-Ethiopian national Sirak Asfaw in a secret location in his Netherlands home.

A former refugee, Sirak fled Ethiopia during the “Red Terror” purges in the 1970s. Over the ensuing years, he hosted Ethiopian pilots, diplomats and refugees as they passed through the city. He unexpectedly became the guardian of the crown in April 1998, after one of his guests left behind a suitcase.

Sirak said he "looked into the suitcase and saw something really amazing and I thought 'this is not right. This has been stolen. This should not be here. This belongs to Ethiopia'".

Sirak refused to let the unnamed suitcase owner regain possession and instead hid it from the regime that had allowed it to be stolen in the first place. “I knew if I gave it back, it would just disappear again”, he told AFP.

One of Ethiopia's most important religious artefacts, the crown is one of only 20 created and is one of the most valuable of those. Made of gilded copper, it features images of the Holy Trinity and Christ's disciples.