The commissioner of the agency, Andrew Treusch, sent an email on Friday to the president of the CBC asking for the data, saying the agency wants to begin work immediately on reviewing the information.
CBC spokesman Chuck Thompson said the corporation rebuffed a similar request from the CRA in 2013 for another massive cache of tax-haven data — and will do so again.
"Simply stated, CBC News does not reveal its sources and we're not about to start now as a result of this request," he said.
Earlier this year, the Panama Papers were distributed electronically to CBC News and other select news organizations around the world, and stories about the contents began to appear this month. The blockbuster revelations are having serious political repercussions in some countries, while others are looking at ways to stop the wealthy from stashing cash offshore to avoid paying taxes.
Panamanian Public Prosecutor Ricaurte Gonzalez (R) conducts an inspection at the offices of Mossack Fonseca, the law firm at the centre of the Panama Papers leak, on April 11, 2016. The CBC, along with other members of the ICIJ, has declined to hand over the treasure trove of leaked data to government authorities. (Getty Images)
The Washington-based International Consortium of Investigative Journalists (ICIJ) is co-ordinating the distribution of the data, and plans to post a subset of the information on a searchable database in early May.
Treusch said in his letter he did not want to wait for the ICIJ posting.
"As you can appreciate, this information would be of greater value to us if obtained in a timelier manner so that we can begin our work immediately," he wrote.
"Please note that we are not asking you to reveal your sources or how you came into possession of the information."
The deputy director of the ICIJ, Marina Walker Guevara, said other tax agencies have approached news organizations in Britain, Italy, Ireland and Latvia, among others, to turn over Panama Papers data, all without success.
Tax agencies have also directly approached the ICIJ, which has a long-standing policy to refuse such requests because it "is not an arm of law enforcement and is not an agent of the government."
Walker Guevara said the posting of Panama Papers data in early May will be a small slice of the information, allowing anyone to search among 214,000 offshore entities and the people connected to them, including shareholders and directors.
But documents, pictures, email addresses, passport numbers and other information touching on privacy will not be posted.
"We believe that information about who owns an offshore company should be public and transparent," she said in an interview.
"So this is going to be a bare bones, searchable database. It's not going to be documents."
On Monday, National Revenue Minister Diane Lebouthillier announced more money and more auditors would be put into tracking down offshore money in tax havens.