The political support groups of Chief Cabinet Secretary Takeo Kawamura logged about ¥22 million in expenditures over the past three years — with almost ¥15 million spent on office and personnel fees — even though the home of his secretary was registered as a rent-free office.

The unusually high numbers have raised suspicions Kawamura used the political funds for other purposes he did not want to disclose and is trying to disguise it.

Kawamura admitted to reporters Thursday that no rent was paid but insisted the office was used for political activities. The apartment in Chiyoda Ward, Tokyo, was owned by the late Tatsuo Tanaka, a former Lower House lawmaker from the Liberal Democratic Party. It was loaned out for free by one of Tanaka's relatives, who inherited the house.

"There is a part of me that took advantage of the goodness" of Tanaka's relative, Kawamura said. "I think I should have explained . . . but it was a place I had been visiting freely since my school days."

The three organizations reported spending ¥1.1 million on office fees and ¥5.05 million on personnel fees in 2005, ¥1.08 million on office fees and ¥4.38 million on personnel in 2006, and ¥960,000 on office fees and ¥2.31 million on personnel in 2007, according to media reports.

The three groups disbanded in March.