Israeli authorities are investigating how the Lord Mayor of Dublin Micheal Mac Donncha arrived in the country despite instructions to bar his entry.
Interior minister Arieh Deri ordered an inquiry after Mr Mac Donncha announced he was in the West Bank city of Ramallah for a conference after landing at Israel's Ben-Gurion airport.
Israel had aimed to block his entry because of his support for the BDS movement, which advocates boycotts against it.
Israel said the campaign, with its call for a return of Palestinian refugees to land inside Israel, goes beyond opposition to the West Bank occupation and masks a deeper aim of destroying the country.
Mr Deri said that upon his departure Mr Mac Donncha would be notified that he will not be allowed back.
Mr Mac Donncha said he knows of no ban on him.
- Digital Desk and Press Association