The bag containing the memory card was discovered it in a walkway alongside the River Wandle in the Haslemere Industrial Estate just before Christmas.
Detective Constable Riaz Karolia of Wimbledon Police said:
"So far we have had no success in locating the owner of this bag. I am hoping that by issuing these images, someone may recognise the people involved and we can start the process of reuniting the owner with their belongings.
"The memory card contains images of someone's special day - if you know who these people are, please get in touch."
More top news
Emotional scenes outside Kings Cross as woman who lost her legs in the 7/7 attacks had an unexpected visit from the man who saved her life.
Dry for most of tonight, with clear spells at first
The officer tried to hold off the group at Finsbury Park - where Drake and Mary J Blige were headlining.