My late brother was a professional photographer in our home town. Back in the 1970s he took photographs of many of the locals who obviously posed for him in street situations. Somehow after his death a box of these photgraphs was donated to the local museum.
From afar I run a community site for locals and expats. The museum informed me that they'd re-discovered this box of photo's and asked would I like to publish them, this I did as a tribute to my brother and for the families of those who were photographed - in all about 30 photographs.
The other day I received the following email asking: "Can you tell me where you got permission to publish the photograph of my late stepfather George - "
Can I quote the museum as my permission - I already state on the webpage the source of the photographs as above. I'd be quiet happy to remove this one photo but would be interested in your comments.
I wonder what kind of permission is being asked about; whether it relates to 'model release' or 'copyright permission'.
If it is the latter then as far as I know the copyright was held by your brother, and then the copyright will have been distributed in some way following his passing away. Whilst I have no idea what happened to that copyright, it is likely to have gone either with the photographs to the museum or to one of the other heirs of your brother's estate - I think you would need legal advice to figure that out.
You might be wrong to assume that this person wants you to remove the image, he or she may well wish to track down the original photograph and get his or her own permission for a family archive or similar.
You will likely require model releases, if not from the actual subject then from their estate or heris.
Also the question of ownership of the rights to the photographs themselves. The photograph copyright may not actually belong to the Museum, they may own the print only. The ownership of the rights to the images may in fact be much more complicated.
I would clarify the type of request that you received from the person asking where you secured permission. Their request may be related to obtaining image rights and be sure to check with an attorney if it sounds like you have a more serious issue brewing.