Jewellery with a value of $16,000 has been dropped off at the City Mission charity shop in Victoria Avenue, Whanganui.
Shop manager Michelle Wilson said a woman had dropped in a parcel of stuff and told staff it was "a donation for the mission". But she is certain the jewellery was included in error.
"When we opened it one of the staff immediately knew it was valuable" said Mrs Wilson.
She doesn't think the donation was deliberate, given the way the jewellery was packaged.
Three experts have examined the jewellery and agreed on an estimated value of $16,000.
"I would know the woman again if she came in I think" said Mrs Wilson.
"So there's either been a huge mistake or someone has really donated it to the mission."
The jewellery has been moved to a safe place and is not on the premises.
If anyone thinks the jewellery is theirs, go to the shop and you will need to identify the goods and give details of when they were dropped off.