Denis O'Brien and the Irish Bank Resolution Corporation have been granted orders by the High Court preventing RTÉ from broadcasting a report about Mr O'Brien's personal banking arrangements with the bank.
Mr O'Brien had sought the order saying he would suffer irreparable harm if the report was broadcast.
Mr Justice Donald Binchy granted the order in Mr O'Brien's favour.
He also granted an order to the bank preventing RTÉ from broadcasting any legal advice given to IBRC arising from the banker-customer relationship with Mr O'Brien.
The judge ruled that none of the contents of his judgment can be reported until lawyers agree on which parts of it should be redacted.
This means that none of the judge's conclusions which were read out in court can be reported.
Lawyers for Mr O'Brien, described as a major debtor of IBRC, had argued that rich and powerful figures were entitled to their privacy as much as anyone else.
Mr O'Brien had said he was trying to stop the broadcast about his confidential, private banking affairs as a matter of principle.
His lawyers had argued that RTÉ was crossing a line in trying to broadcast the precise size of his loans with the IBRC, the precise repayments he had made and the precise speed with which he had made them as well as the details of his negotiations with the IBRC.
The court heard there was nothing in the proposed script of the report by RTÉ's Business Editor David Murphy suggesting any wrong doing by Mr O'Brien.
However, lawyers for Mr O'Brien said the disclosure would make other financial institutions unwilling to deal with him and damage him commercially in a way he would never be able to prove.
He said there was not sufficient public interest to displace his right to privacy and confidentiality and his contract with his bankers.
The court heard Mr O'Brien believed the proposed report was "outrageous" prying into his private banking affairs in a report of which he was not the focus.
He said the information was acknowledged to be confidential to him and there was no suggestion of wrong doing.
It was clearly trying to use his confidential information to promote this proposed story about the corporate governance of IBRC. He was being placed in an invidious and unique position compared to other citizens.
RTÉ had argued that the story was about the business relationship between Mr O'Brien and the bank.
Lawyers for RTÉ said the right to privacy with which this case was concerned was not weighty enough to outweigh the right to freedom of expression because it related only to business affairs.
RTÉ had argued Mr O'Brien was Ireland's most powerful media baron and its lawyers had argued he was not a private person but a public figure.
They said he was not entitled to control how much the public should know about him.
They also said that broadcasting the report without using Mr O'Brien's name would suck the lifeblood out of the story.
They said RTÉ was just trying to put some flesh on the bones on what was already in the public domain. Allegations in relation to this story had already been made in the Dáil by independent TD Catherine Murphy.
They said it was State money we were dealing with in relation to Mr O'Brien's loans with IBRC.
If it was the case that Mr O'Brien was allowed to pay off loans in his own time, lawyers for RTÉ said that was the conferral of a very significant financial benefit.
Mr Justice Binchy said there was not much that needed to be redacted in the conclusions to his judgment.
However, after a brief discussion with lawyers, it was agreed that none of the judgment could be reported until agreement was reached about redactments to the entire judgment.
Lawyers for RTÉ raised concern about the scope of the proposed orders to be made by the court.
Senior Counsel David Holland said other media organisations could be prevented from running a story if they received information of a similar kind which came into their possession from a different source.
Mr Holland said Mr O'Brien was seeking an advantage over the entire press corps of this country.
He said the order should be limited to stopping publication of information in the possession of RTÉ.
Although he acknowledged there was a difficulty as RTÉ had not revealed what documents it had.
Mr Justice Binchy did not give such an order, but he did allow liberty to apply to the court to any party who may be affected by his order.
In a statement this evening, Mr O'Brien said he was delighted with the ruling.
He said: "RTÉ came into possession of highly selective illegally obtained documents and took a decision to attempt to broadcast the details."
He said he took the case to protect his rights as a citizen.
"I believe that every citizen is entitled to privacy in their financial affairs, he said.
He added: "I believe that the circumstances of today's decision should be a matter of the gravest concern for the RTÉ Authority as the national broadcaster."
Independent TD Catherine Murphy said she was alarmed at the all encompassing nature of today's ruling.
She said there was nothing she could say about the issues of the case because of the extremely wide ranging injunction.
However, she said there were very serious implications here for the freedom of the press and said how we proceed on this matter was crucial for future reporting and democratic process in this country.