Japanese individuals and companies listed in the leaked Panama Papers owe more than ¥1 billion ($9.06 million) in taxes on undeclared income, sources close to the matter have said.

This is the first calculation by Japanese tax authorities of the amount owed on the undeclared income exposed by the documents, which detail how the rich and powerful use tax havens to hide their wealth.

The names of the individuals and companies found through the papers to owe taxes on undeclared income have not been disclosed, but no irregularities involving politicians were apparently uncovered, the sources said.

The unpaid taxes came to light through investigations after the individuals and companies were each contacted by local tax authorities. Most of the income itself was determined not to have come from illegal activities, though some irregularities were found in cases involving domestic deals, the sources said.

The Panama Papers refers to leaked internal files from the Panama-based law firm Mossack Fonseca & Co., which specializes in shell companies. The files contained information on over 200,000 offshore entities connected to people in more than 200 countries and territories.

The Panama Papers showed individuals and companies in Japan, including major trading firms Marubeni Corp. and Itochu Corp., were listed as shareholders or directors of at least 270 entities in offshore tax havens.