The Grand-Mère Inn in Shawinigan was the focus of the National Post's investigation. (CBC)The Supreme Court of Canada says journalists have no constitutional right to protect confidential sources at all costs, in a ruling against the National Post that could have major implications for press freedom.

The top court ruled 8-1 against the newspaper and journalist Andrew McIntosh, in a case linked to the 10-year-old so-called Shawinigate scandal that involved former prime minister Jean Chrétien, a hotel in his home riding and questionable bank documents.

McIntosh and the Post were attempting to quash a search warrant issued nearly 10 years ago in the case that would have forced them to provide RCMP with the documents, which McIntosh obtained from a confidential source known as "X."

"The law should and does accept that in some situations, the public interest in protecting the secret source from disclosure outweighs other competing public interests – including criminal investigations," Justice Ian Binnie wrote on the Ottawa-based court's behalf, in a ruling released on Friday.

"In those circumstances, the courts will recognize an immunity against disclosure of sources to whom confidentiality has been promised."

McIntosh, who no longer works for the National Post, promised "X" confidentiality and stored the documents in a safe place.

RCMP sought the documents via a search warrant after the Business Development Bank of Canada called them forgeries.

The Supreme Court's justices said claims of immunity can be argued on a case-by-case basis, but there is no broad legal protection to shield sources. In certain cases, such as this one, the court said police investigation needs override confidentiality.

Brown envelope passed to paper

In 2000, the investigative reporter was looking at potential links between Chrétien and the Grand-Mère Inn, a hotel in his home riding of Shawinigan, Que.

McIntosh obtained the bank documents from "X" around this time, and the paperwork appeared to be internal loan forms connecting the inn to a Chrétien family corporation.

McIntosh has already testified his source told him the documents arrived by mail anonymously, and "X" passed them along, believing them to be real.

When the BDBC said the documents were forgeries, RCMP were called in and requested them for testing. The Mounties obtained a search warrant and assistance order asking the newspaper to assist in locating the documents.

Ontario's Superior Court struck both orders down, but the province's Court of Appeal later reinstated them.

Decision hurts press freedom: liberties association

The court decision has major implications for the journalist-source relationship, said the B.C. Civil Liberties Association (BCCLA), an intervener in the case.

"We all rely on that relationship to get the news and issues of great national importance, such as this one," said Tim Dickson, who acted as counsel for the BCCLA.

"It's because of the willingness of confidential sources to come forward. But they only come forward because they're promised confidentiality."

It's disappointing to see the country's highest court miss a chance to "set a high bar" for journalist-source relationships, Dickson added.

"That relationship is so important to freedom of the press, and having the news be brought out to the public."

With files from The Canadian Press