Tax authorities say Sedic International Inc., a film production firm known for its Oscar winner "Okuribito" ("Departures"), failed to declare about ¥1 billion in income in the five years to August 2012.

The Tokyo Regional Taxation Bureau levied about ¥400 million in back taxes, including a heavy additional tax, after finding that part of the revenue from the 2008 film was not reported, bureau sources said on Wednesday.

Sedic International has since corrected its income declaration and paid the back taxes and fine. The tax authorities added the fine because they believe the company actively tried to hide its income.

Besides planning and producing films, the Tokyo-based company manages artists as well.

It failed to report several million yen earned in theaters and from DVD sales for "Okuribito," which won the Oscar for best foreign-language film in 2009, the sources said.

The company also apparently did not declare overseas revenue from its 2010 film "Ju-san Nin no Shikaku" ("13 Assassins"), the sources said.