The Tokyo Regional Taxation Bureau has found that a unit of the developer of online game Fortnite failed to report some ¥30 billion in revenue from in-game spending, sources said Wednesday. The problem, which lasted for three years to December 2020, was uncovered in an investigation by the tax bureau. The bureau concluded that some ¥3 billion in consumption tax was left undeclared, slapping the unit with back taxes and penalties reaching an estimated ¥3.5 billion. It is believed to be an unusually large amount imposed on a foreign company as a result of a tax investigation. Fortnite is a popular online game developed by Epic Games of the United States. It is estimated to be played by over 400 million people worldwide via personal computers, game consoles or smartphones.