The Department of Foreign Affairs is liaising with police in Spain after three members of the same family were found dead in the Costa del Sol.
The nationalities of the victims have not been confirmed.
A man, a woman and a young woman, believed to be their daughter, were discovered in a rented property in Mijas, Fuengirola.
A Guardia Civil spokeswoman earlier said the family were British, but a spokesperson for the Department of Foreign Affairs said it is investigating reports that Irish nationals were involved.
The British Foreign Office is also investigating the deaths.
Mijas is a popular town with a reputation for being family-friendly with its many cafes and restaurants.
