A man suspected of killing six people in a spree of murders in Japan is the brother of Peru’s most prolific serial killer, known as "The Apostle of Death".

Vayron Jonathan Nakada Ludeña was taken into custody by police in a suburb of Tokyo following the murder of six people in three homes this week.

The 30-year-old is reported to be the brother of Pablo Nakada Ludeña, who killed 25 people in Peru between 2000 and 2006 who he considered to be drug addicts, prostitutes, homosexuals, and criminals that God had ordered him to kill.

Vayron Nakada Ludeña remains unconscious in hospital with a fractured skull after falling from the second storey of one of the victims’ homes while being pursued by police.

Japanese news agency Kyodo reported that he attempted suicide by cutting his wrists before he fell.

He is the prime suspect in the killings of six people including a woman and her two daughters, aged seven and 10, who were found dead in wardrobes in their home in the residential neighbourhood of Kumagaya, northeast of Tokyo on Wednesday.

An 84-year-old woman was also found dead hours earlier in the bath at her home around 100m away.

A couple in their 50s were stabbed to death in their home in the same local area on Monday.

Vayron Nakada Ludeña is suspected of killing the victims randomly after fleeing a police station where he was being questioned on Sunday, after being found in an incoherent state in a fire station.

The suspect's older brother, Pablo Nakada Ludeña, 42, has been held in a psychiatric prison in Peru since his arrest in 2007.

In 2011, he gave a television interview from prison in which he said: "I am not a criminal, I’m a cleaner, I got rid of homosexuals and the homeless from society. I killed 25 people to clean the world of scum."