The detention of a Belfast man for questioning by the Israeli authorities was being widely described last night as a case of mistaken identity.
Seán Ó Muireagáin, who was named in the Israeli media as John Morgan, is a well-known campaigner on issues related to the Irish language and the cause of the Palestinians.
He is also a part-time journalist who was dispatching articles from the West Bank for the Irish-language newspaper, Lá.
Irish-language activists and journalists in Belfast strongly defended Mr Ó Muireagáin yesterday and called for his immediate release.
Meanwhile, senior republican sources said Mr Ó Muireagáin had "no connection whatsoever" with the movement.
The sources claimed that the arrest was "a deliberate set-up" by British Intelligence.
Mr Ó Muireagáin is reported to be travelling on a British passport and it is understood that the British embassy in Israel was seeking consular access to him last night, in line with his entitlements under the terms of the Vienna Convention.
There was no official comment from the Israeli Government Press Office at the time of going to press.
However, there was some speculation last night that there could be an early development - possibly the release of Mr Ó Muireagáin.
Senior Israeli sources said the reason there had been no official comment was because the interrogation was still under way and they complained that some of the more lurid coverage in the news media "didn't do us any service".
Friends of Mr Ó Muireagáin in Belfast said he was between jobs and was using the interlude to make an extended visit to the Palestinian Territories.
Originally a full-time teacher of Irish at primary level, he took up a position with Comhairle na Gaelscolaíochta, the council for Irish-language schools, set up under the Good Friday agreement.
He is due to take up a new post shortly, with Gaeloiliúint, an organisation dedicated to promoting third-level education through Irish.
He was also described as a committee member of the Belfast branch of the Ireland Palestine Solidarity Campaign, which also has branches in Cork and Galway.
Unconfirmed reports said he was stopped last week, either on Thursday or Saturday, at an Israeli checkpoint near Ramallah, along with eight other solidarity campaigners.
The others were all let go, but Mr Ó Muireagáin was held for questioning by Shin Bet, Israel's internal security service, reportedly acting at the suggestion of British Intelligence.
Speaking from Belfast yesterday, the managing editor of Lá, Mr Máirtín Ó Muilleoir said: "He has no involvement in politics here at all: his twin passions are the Irish language and Palestine."
Mr Ó Muireagáin is chairman of the board of governors of the Irish-language school, Bunscoil an tSléibhe Dhuibh in west Belfast.
The principal of the school, Mr Pilib Mistéil, said: "We had agreed to task him with linking our school with a primary school in Jenin. He was undertaking that task while in Jenin.
"His arrest is a disgrace, the allegations made against him are scandalous and he should be set free immediately."
A spokesman for the Department of Foreign Affairs said: "The family have been in touch with us and our embassy in Tel Aviv are talking to the British Embassy, but because he travelled on a British passport we have no legal or consular standing in the matter."