Prosecute,,make these guys sweat under the fear of a long prison sentence...one of them will break and rat out the others.
If the primary data was thrown out, then this is not science. If you can’t verify results, and the data presented are significantly altered/filtered, then you can’t trust the data. It’s that simple. This is even more compelling when you are sitting on emails that talk about dumping data rather than releasing it.
Also, did the primary sources of all this data dump it (i.e. the specific stations at which the measurements were taken)? If not the raw data should be retrievable.
Given the economic implications of all this there should be a massive investigation.