Tax authorities on Thursday raided the house and company in Yokohama of a senior secretary of LDP lawmaker Koichi Kato, investigative sources said.
Saburo Sato, 61, who serves as a representative of Kato's office, is suspected of hiding hundreds of millions of yen in income.
Sato oversees the accounting for Kato's Tokyo-based fund-management body, and is widely known in political circles as the "safe-keeper" of the former Liberal Democratic Party secretary general.