Ysyry (2013)

The story takes place in Luque, on the banks of the Yukyry stream, where Juanchi is going to take a dip after playing soccer on a hot summer afternoon. The child plays innocently in the stream when he suddenly shows respiratory failure after ingesting some water. It happens what is least expected, all the people dress in mourning for the tragic death of this child, thinking that he died drowned when in fact it was something else. The child's sister and the local doctor begin an investigation and that's when they'll wish they'd never started it by learning everything that's going on behind it.

Unfortunately the movie Ysyry is not yet available on HBO Max.