The European Union's Special Representative for Human Rights has said the release of Dublin man Ibrahim Halawa from an Egyptian prison remains top of his agenda.
Stavros Lambrinidis has raised the 21-year-old's imprisonment with authorities on several visits to Egypt.
It is a month since Mr Halawa was acquitted of all charges related to a mass protest in Cairo.
However, he remains in custody, where he has been since his arrest in 2013.
Mr Lambrinidis said: "I am extremely familiar with the story. I have raised it personally during my seven visits to Egypt over the past few years.
"The Higher Representative of the European Union has raised it. It is a case that has been of great interest to us. We have worked very closely with the Irish government on this as well."
Mr Lambrinidissaid he was pleased that the case against Mr Halawa was dropped, but he is not pleased that he has not yet returned home.
He said he will keep working to ensure that this happens.
Mr Lambrinidis is in Dublin for a conference on human rights called Dublin Platform for Human Rights Defenders, where the issue of protecting activists at risk is being discussed.