Royal Bank of Canada, one of the financial institutions mentioned in the massive leak of documents revealing the use of offshore tax havens by individuals including heads of state, superstar athletes and billionaires, says it has a rigorous process in place to prevent illegal client activity.

Data from 11.5 million documents reportedly from the Panamanian law firm of Mossack Fonseca includes information on offshore companies allegedly linked to 12 current or former heads of state or government, their associates or family members, including Russian President Vladimir Putin, Chinese President Xi Jinping, the late father of British Prime Minister David Cameron, Ukrainian President Petro Poroshenko and Icelandic Prime Minister Sigmundur David Gunnlaugsson.

Among dozens of financial institutions mentioned, the documents allege that RBC regularly used the services of Mossack Fonseca, with about 370 corporations set up through the firm.

“RBC works within the legal and regulatory framework of every country in which we operate,” the bank’s spokeswoman Tanis Feasby said in an e-mail Monday.

“Tax evasion is illegal, and we have established controls, policies and procedures in place to detect and prevent it occurring through RBC.”

The bank has an extensive due diligence process to make sure it knows the client and what his or her intentions are and “we will not proceed with a transaction until we do.

“There are a number of legitimate reasons to set up a holding company. If we have reason to believe a client is seeking to commit a criminal offence by evading taxes, we would report the offence and not do business with the client.”

The data were leaked to German newspaper Sueddeutsche Zeitung and analyzed by the International Consortium of Investigative Journalists (ICIJ), which has been involved in a series of similar data dumps on offshore tax evasion.

- With a file from Jeff Gray