"All searches came to a halt when the Colombian government declared the lake a protected area in 1965. " ... of course. If any were found it would have to be handed over to the government. Same thing occurred when a diving team found a tonne of gold at the bottom of the ocean, it was proven to be Portugal's from a sunken ship hundreds of years ago and had to be handed over to their government.
Lets go find it, I have a shovel and a compass! I only have 2 bags of Doritos though so you will need to provide your own food.
I heard that one expedition managed to drain the whole lake but the sun baked the mud rock hard and they couldn't dig into it.
I always thought if u found anything valuable in any sea or ocean-then its finders keepers.I believe gov's dont "own" those....