This is a complex question. You should answer it thinking about it's historiographical and ethical elements. You must weigh these elements and choose the ones you think are most fairer.
Historiographical elements:
- When it comes to African artifacts, they were stolen in colonial forays that killed thousands of people and many times were genocidal. These thefts consist of cultural and political violence that first took place accompanied by physical violence. In this way, keeping these artifacts in Europe is like a continuation of these colonial forays.
- Large knowledge about the past was produced due to the presence of these stolen African artifacts in Europe. On the other hand, it restrained Africans from also studying them.
Ethical elements:
- Is it just that scholars from these places have easier access to these artifacts than people from where these objects were stolen?
- Is it just to keep artifacts that were stolen?
- is it ethical to stop researches in progress?