Six men, including a senior member of a religious organization, were arrested Wednesday alleged involvement in the slaying of a 70-year-old real estate agent in Tokyo, according to sources.

Yoshisuke Watanabe, 47, one of the key members of the Tokyo-based religious organization, is suspected of masterminding the death of Toshiharu Maruyama, who was killed inside his home June 9, 2001.

Maruyama's wife, who was a member of Watanabe's religious group, was expected to donate her husband's assets to the organization upon his death.

Watanabe, who lives in Nishitokyo in western Tokyo, and the other men allegedly visited Maruyama's home, pretending to be employees of a delivery firm. When Maruyama opened the door, he was shot dead.

Police suspect Watanabe asked his underworld connections to recruit the assassins. Investigators have already determined how they obtained the handgun and where they disposed of the weapon, sources said.

Maruyama came into conflict with the group over money he loaned to the organization at his wife's request. When Maruyama later asked for his money to be returned, the organization told him it considered the money a donation and refused to pay, the sources said.

Maruyama's wife left the group after her husband was killed and never donated his assets to the group, the sources said.

Watanabe's group was officially recognized as a religious organization with corporate status. It was involved in counseling, religious service and the sale of seals. At its peak, the group had about 100 followers, the sources said.