Where does the elevation data in this area come from? There are numerous large spikes in this data which are not present in real life...

This spike is fictional. How can I tell? Because it says the top is at an elevation of 5740 metres. The highest real mountain on the island of New Guinea is Puncak Jaya (4884 metres). There are many, many of these obviously fictional spike in the elevation data for PNG / Papua. Where did the data come from?

This enormous spike does not exist in real life. There are many, many such spikes in the elevation data in Papua and in PNG that are fictional. Where does this elevation data come from?