Ireland's highest court today threw out an order compelling two journalists to answer questions about an article uncovering payments to ex-taoiseach Bertie Ahern.
Irish Times correspondent Colm Keena and editor Geraldine Kennedy faced a grilling from the Mahon Tribunal after the High Court backed the inquiry's demand to question the pair.
But the Supreme Court said it could not see any benefit to the planning corruption inquiry in upholding the order.
Ms Kennedy heralded their legal victory as a triumph for investigative journalism.
"We're happy that this saga has come to an end, that we're not being sent off to protect our sources," she said.
"It's very important because for the first time the right of journalists to protect their sources is enshrined in Irish law and it's very important that that's being done now by the Supreme Court."
Mr Keena said he was delighted with the outcome.
"I was very anxious about the whole matter and delighted that the Supreme Court listened to our arguments and gave the judgment it gave and they recognised the importance of the story," he said.
"They recognised that we were acting in the public interest in publishing the story, so I'm delighted with that."
The article at the centre of the case, written by public affairs correspondent Mr Keena in September 2006 revealed the inquiry was investigating payments to Mr Ahern in 1993 when he was Finance Minister.
Both journalists were summoned before the tribunal about the source of the article but declined to answer questions.
High Court proceedings were initiated and in October 2007 an order was made compelling them to answer, but the newspaper appealed the decision to the Supreme Court.
The Irish Times article sparked months of controversy surrounding Mr Ahern's finances in the lead up to his surprise resignation in April 2008.
The National Union of Journalists welcomed the judgment as a victory for press freedom.
Seamus Dooley, Irish secretary, said: "This is a welcome restatement of the right to protect confidential sources of information.
"It is regrettable that Ms Kennedy, Mr Keena and The Irish Times were forced to go to the Supreme Court to vindicate this important journalistic principle but the judgment is one, which is extremely important."Reuse content