A 63-year-old Saitama Prefecture man has been arrested on suspicion of attempting to extort money from a Tokyo hospital owner, the Metropolitan Police Department said Monday.

Police said the man has confessed to well over 100 similar extortion attempts targeting scandal-hit firms and public figures.

Juichi Ishizaki, a Kawaguchi resident, was arrested for allegedly attempting to extort money from the owner of a hospital, who was reported to have dodged tax payments, by sending a letter in which he pretended to be a lawyer for a gangster group.

Police said Ishizaki confessed to sending similar extortion letters to other major companies as well as more than 100 business executives and politicians who had received media attention for accidents or scandals.

His targets included Recruit Co., which was at the center of a major shares-for-favors scandal that surfaced in 1988, as well as JCO Co., operator of a nuclear-fuel processing facility hit by the nation's worst nuclear accident in 1999 in Tokai, Ibaraki Prefecture, police said.

None of the extortion attempts were successful, they said.

In the hospital case, Ishizaki allegedly sent a letter around July 20 to the 76-year-old owner of a hospital in Itabashi Ward, Tokyo, in the name of a lawyer hired by the major underworld syndicate Yamaguchi-gumi.

Ishizaki allegedly wrote that the owner hid 1 billion yen in income to dodge taxes and requested that he donate 33 million yen to a welfare project, adding that he would send the owner's family and employees to "the next world," according to police.