Police on Sunday served a fresh arrest warrant on charges of murder to Hikaru Sasaki, one of six people held over the case of a Tokyo businessman and his wife whose charred remains were discovered in Tochigi Prefecture in April.

Sasaki, 28, is the second person to be hit with charges of murder in the killing of corporate executive Ryutaro Takarajima, 55, and his wife, Sachiko, 56. Sasaki, whose occupation is unknown, was arrested earlier for his alleged involvement in burning the bodies of the couple. Construction worker Ryoken Hirayama, 25, was the first suspect in the case to be charged with murder.

A joint investigation team of Tokyo's Metropolitan Police Department and the Tochigi Prefectural Police suspects that Sasaki was asked by a mastermind of the high-profile crime to find a person to carry out the murder, and was involved in tasks such as conveying related information and providing a payout for the killings.