Dr Costello has published widely on many aspects of EU and human rights law, including asylum and refugee law, immigration, EU citizenship and third country national family members, family reunification and immigration detention. She also researches the intersections of immigration, asylum and labour law.
She has undertaken research for UNHCR, the Council of Europe and the European Parliament. She previously served on the boards of both the Irish Refugee Council and Immigrant Council of Ireland, and contributes to the policy work of ILPA (Immigration Law Practitioners Association).
- International refugee law
- EU refugee, asylum and migration law
- Human rights of refugees and migrants
- Immigration detention
- Forced labour, in particular concerning migrant workers
Dr Costello has considerable experience of working with the media and has been interviewed on Europe's ongoing migration crisis by a number of outlets including the BBC, the BBC World Service and HuffPost Live.