Lawyers have asked prosecutors not to appeal a recent court decision granting a retrial to Hakamada Iwao, who is 87 years old.

Hakamada had been sentenced to death for the killing of four people in Shizuoka prefecture, central Japan, back in 1966. After lengthy appeals, the Tokyo High Court ordered a retrial on Monday.

Hakamada's lawyers visited the Tokyo High Public Prosecutors Office on Thursday to ask that the court's decision not be appealed.

At a news conference later, the lawyers gave their views on the prosecution's claim.

The key point of contention at the high court trial was the color of blood stains on five clothing items that allegedly belonged to Hakamada. The clothes were found in a tank of miso, or fermented soybean paste, more than a year after his arrest.

Prosecutors said the experiment on the blood stained cloth soaked in miso for more than a year proved the possibility that the color of dark red remained.

An expert on color examined the photo of the cloth at the request of the lawyers. The experiment found that blood stains soaked in miso for a long time lost its color, while the color of miso became vivid.

The lawyers point out that what prosecutors say about the dark red is not blood stain but the color of miso. They plan to present the analysis to the supreme court if prosecutors appeal.