Prosecutors in Tokyo raided the office of one of the most powerful figures in Japan's governing party on Wednesday, expanding the latest in a series of finance scandals that have sapped support for the new government. Prosecutors searched the office of Ichiro Ozawa, the secretary-general of the Democratic Party, as part of an investigation into what Japanese news reports said was more than $4 million in improperly reported political funds linked to one of Japan's largest construction companies. The investigation comes as polls show falling public approval ratings for Prime Minister Yukio Hatoyama, who has also faced a scandal of his own over millions of dollars in improperly reported political funds. The scandals have appeared to undermine Hatoyama's promises to end the insider-driven politics of his predecessors, the Liberal Democratic Party, whose half-century rule his Democrats ended in August. The inquiry has also focused public attention on the growing influence of Ozawa, a veteran political strategist and dealmaker who is widely seen here as the power behind the throne in the new government. Political experts describe Ozawa's control of the party's purse strings, and its campaign to win crucial parliamentary elections this summer, as giving him power rivaling that of Hatoyama. News reports have been critical of Ozawa for apparently brushing off requests from prosecutors to answer questions about his role in the financing irregularities. While Ozawa has told prosecutors that he is too busy to talk with them, news reports have showed him greeting supporters and even sitting down to play Go, an ancient game of strategy. On Tuesday, Ozawa held a news conference to apologize. 'As I have said many times, there may have been miscalculations by myself or those in my office, but I believe that there was no intentional violation of the law,' Ozawa told reporters. Prosecutors also searched the company, the Kajima Corp., as well as the offices of Tomohiro Ishikawa, a former aide of Ozawa who is now a Democratic lawmaker. This is the second time in less than a year that prosecutors have investigated Ozawa, who resigned as Democratic Party leader last spring after a similar financing scandal involving another construction company. 