Police arrested nine people Monday, including board members of Seibu Railway Co., over their suspected involvement in the firm's alleged payoff of a "sokaiya" corporate extortionist to ensure that its shareholders' meetings went smoothly.

The Metropolitan Police Department arrested Seibu's senior managing director, Seiichi Ikura, 65, and five others, including board directors Norihiro Kanno, 59, and Masaru Kojima, 55, on suspicion of paying off well-known sokaiya Ryuga Haga, 74, investigative sources said.

Police suspect that Ikura arranged bargain real estate deals in 2001 via a Seibu Railway subsidiary, enabling the sokaiya and his associates to pocket around 88 million yen.