Please help share if you have friends in SengKang/ Punggol area.
Found a set of keys at the PCN opposite Punggol Marina. Two foreign workers found it actually. Kudos to them, as they were so nice as to wait around for 2 hours for the owner to come back. Eventually they wave me down while I was passing on my bike. I told them I'll passed them to the police.
Which is what I did. They're now at SengKang police station, so please claim it if it's yours. Seems like a lot of keys to lose, so I hope the person will see this post.