Police arrested three men Thursday on suspicion of torching a warehouse for insurance money in 2003 in Sakura, Tochigi Prefecture, a day after they arrested another man on the same charge.

Police suspect that auto sales/repair shop owner Hiroshi Kobayashi, 58, and two others, as well as hotel employee Yoshio Ban, 47, who was arrested Wednesday, burned Kobayashi's warehouse to the ground in order to get insurance money.

Police Thursday searched the home of Kobayashi, whose wife, 41, was found hanged in his shop in February. They suspect foul play in her death because an autopsy found marks of strangulation on her neck in addition to rope marks. Kobayashi stood to receive 90 million yen as the beneficiary of her life insurance policy.

The wife's death followed the fatal fall from an apartment building of her second son, 7, in February 2004. Again, Kobayashi received about 80 million yen in insurance money from his stepson's death.

Police have not said, however, if they suspect Kobayashi of being behind the wife's and stepson's deaths, or if he was questioned as a suspect when they determined the wife had been murdered.

Two of the arson suspects, including Kobayashi, denied setting the fire, but Ban and the fourth suspect have owned up to it, police said, without naming the other suspect.

Kobayashi received about 6 million yen in insurance benefits from the fire. Police plan to question the four men, believing they planned to cash in on the fire.

Kobayashi married in April 2003. The wife's second son fell to his death from the apartment building in February 2004. The death was treated as an accident at the time, police said.

Kobayashi is the beneficiary of his wife's 90 million yen policy, but has yet to be paid.