WASHINGTON (AP) — Calls grew Monday for an end to the financial secrecy that has allowed many of the world's richest and most powerful people to hide their wealth from tax collectors.

The outcry came after a report revealed the way that world leaders, billionaires and others have used shell companies and offshore accounts to keep trillions of dollars out of government treasuries over the past quarter-century, limiting the resources for helping the poor or combating climate change.

The report by the International Consortium of Investigative Journalists brought promises of tax reform and demands...