Five charred bodies were found inside a burnt van at Koshenwatta, Irabadagama in Dankotuwa on Friday (11) morning.
Investigations reveal the five persons would have been killed over a ransom demand.
Police followed a lead to the owner of the van, a woman residing in Colpetty, who had leased the vehicle to a private financial company.
Later it was found that the company has offered the van to a person from Kajuwatta, Makandura who recovers vehicles under lease with due instalments.
It is reported that this person offers money on interest, and engages in several illegal businesses, in addition to being charged for murder and theft.
The person was identified as Senarath Kapila Bandara alias Navy Kapila from Dankotuwa.
He has been constantly threatening several people demanding ransom within the last few months. A group of persons who were subjected to his threats had awaited the arrival of Navy Kapila to Dankotuwa, and burnt the van in which he was traveling.
Four associates of Navy Kapila are among the dead.
CID sources stated that the five arrested persons have confessed to the killings and are to be produced before the court.