1. A geographical region, location, or zone that is currently being examined or studied by authorities, researchers, or officials
The police cordoned off the area under investigation to prevent contamination of evidence.
A polícia isolou a área sob investigação para evitar a contaminação de evidências.
2. A specific domain or field of inquiry being actively researched or examined
Climate change is an important area under investigation by environmental scientists.
As mudanças climáticas são uma área sob investigação importante para cientistas ambientais.