Suzuki Motor Corp. was found by tax authorities to have concealed around ¥300 million in income over two years through March 2015, sources close to the matter said Tuesday.

The automaker failed to declare ¥1.2 billion partly due to accounting errors and has been levied around ¥450 million in back taxes, including a heavy penalty tax, the sources said, saying the total is an estimate.

"We had miscommunications within our company and also didn't have enough knowledge about tax affairs," said a Suzuki Motor official. "Although there was a difference of opinions (with tax authorities), we filed corrected tax reports and paid all of the money levied."