Photo/Illutration Officers escort Seiha Sekine from the Osaki Police Station in Tokyo’s Shinagawa Ward on May 7. (Kazushige Kobayashi)

Two more men have been arrested in connection with a couple’s charred bodies found last month in Tochigi Prefecture, including the suspected mastermind of the scheme, investigative sources said.

Six people are now accused of involvement in the burning of the corpses of Tokyo businessman Ryutaro Takarajima, 55, and his wife, Sachiko, 56.

But so far, no one has been formally accused of murdering the couple, who lived in Chiyoda Ward in the capital.

Information released by police sources is painting a clearer picture of what happened to the Takarajimas.

Tokyo’s Metropolitan Police Department and Tochigi prefectural police on May 7 arrested Ryo Maeda, 36, a real estate company executive and acquaintance of the couple.

According to investigators, Maeda met the couple in Tokyo’s Ueno district at around 9:30 p.m. on April 15 and drove them in a rental van to an abandoned home in the capital’s Shinagawa Ward, where they were attacked.

Police have not disclosed whether Maeda, from Funabashi, Chiba Prefecture, has admitted to or denied the allegations.

On May 6, police arrested Seiha Sekine, 32, the partner of the dead couple’s daughter and the likely “brains” behind the crime, the sources said.

Sekine, from Tokyo’s Setagaya Ward, has managed at least three restaurants owned by the Takarajimas in the Ueno district, according to the sources.

The suspect met the couple while working part-time at one of their restaurants and later developed a relationship with their daughter, they said.

Sekine now serves on the board of a restaurant operating company owned by the daughter. He also runs his own restaurant business.

According to investigators, after Maeda drove the couple to the vacant home in Shinagawa Ward, they came into contact with Kang Gwang-gi and Kirato Wakayama at around midnight.

Their burned bodies were found on the morning of April 16 at a riverbank in Nasu, Tochigi Prefecture, 150 kilometers north of Tokyo.

Police believe the victims were killed before their bodies were set on fire.

Kang and Wakayama, both 20, were arrested on May 1 in connection with disposed bodies.

Police also arrested Hikaru Sasaki, 28, and Ryoken Hirayama, 25, last month on the same allegations.

(This article was written by Minami Endo, Shomei Nagatsuma and Hiromichi Fujita.)