The Internal Revenue Service has reportedly filed a tax lien for more than $18.3 million against Filipino boxer and politician Manny Pacquiao.

The unpaid taxes date from between 2006 and 2010, according to TMZ. Tax authorities in the Philippines have also filed claims against Pacquiao for over $50 million in taxes dating back to 2008 and 2009 from his boxing matches in the United States and have moved to freeze his bank accounts and seize one of his properties in Manila.

The fighter, nicknamed “Pac-Man,” reportedly fought 12 lucrative matches in the U.S. during the period in which the IRS is claiming back taxes, including a 2008 bout with Oscar De La Hoya in which he was guaranteed between $15 million and $30 million, and a 2009 fight with Ricky Hatton in which he earned $30 million.

The former eight-division world champion, who has won 10 world titles across different weight classes, fought last month in Macau after specifically requesting not to box in the United States, citing the high tax rates. As a foreign athlete who is not a U.S. citizen or resident, he only has to pay U.S. taxes on money he earns in this country.

Pacquiao’s manager and financial advisor told a newspaper in the Philippines that they have been discussing the tax issues with the IRS for over three years and that it is being handled by their attorneys in the U.S.

Pacquiao had hired a U.S.-based accounting firm, VisionQwest, to straighten out his finances, but they parted ways. His attorney claimed the firm made numerous errors and gave him “substandard accounting and tax advice.”

The firm sued Pacquiao in 2011 for breach of contract and non-payment of fees and disclosed that his manager was paying himself “ridiculous amounts of money” from the fighter’s earnings. Pacquiao then countersued the firm.

In addition to his boxing career, Pacquiao has served in the Philippines House of Representatives since 2010.