The police have arrested two more individuals in connection with the murder of a Tokyo couple whose burned bodies were discovered in Tochigi Prefecture last month, bringing the total number of arrests made in the case to six.

A joint investigation team comprising the Metropolitan Police Department and the Tochigi Prefectural Police arrested Ryo Maeda, 36, who works in a real estate business, on Tuesday, following the arrest of Seiha Sekine, the 32-year-old common-law husband of the Tokyo couple's eldest daughter, late on Monday.

The two men — along with four others arrested earlier — are suspected of being involved in the torching of the bodies of Ryutaro Takarajima, a 55-year-old businessman, and his wife Sachiko, 56, in mid-April.