The lack of U.S. citizens named in the Panama Papers has left Microsoft founder Bill Gates a little incredulous.

A massive anonymous data dump of 11.5 million encrypted internal documents from Panamanian law firm Mossack Fonseca has shed light on the hidden financial dealings of politicians and public officials around the globe. But many commentators were left wondering why so few U.S. citizens were mentioned.

"I was surprised there were so few Americans," Gates quipped to CNBC in an exclusive interview in Qatar.

"Whenever you file your tax return, you are asked to declare what overseas bank accounts and assets you have. It doesn't mean that everybody, absolutely answers that question correctly," he said.

Bill Gates Lacey O'Toole | CNBC

Preliminary reports indicate that more than 200 people with U.S. addresses are named in the Panama Papers, Forbes reported this week. The International Consortium of Investigative Journalists, one of the teams that has been analyzing the data, has said more than 214,000 offshore entities appear in the leak, connected to people in more than 200 countries and territories. CNBC has not been able to independently verify the assertions.

Many reasons have been bandied around for the lack of Americans, with the most notable leaks so far focusing on associates of Russian President Vladimir Putin, U.K. Prime Minister David Cameron and Icelandic Prime Minister Sigmundur David Gunnlaugsson, who stepped aside as head of government after his name surfaced.

Some theories conclude that Mossack Fonseca wasn't a favorite law firm among Americans, while others suggest that the U.S. has its own flexible entity structures and corporate tax breaks. Many pundits also suggest that it is easy for U.S. citizens to create shell companies in certain states.