He had left home at Pallikathodu in Aanikad West towards the workplace on Tuesday; however, he drove his car towards the level crossing at Muttambalam area and threw himself before a passing train.
The police said the girl's father Abdul Sattar and cleric Muhammad Uwais were arrested on a complaint that the girl, who had a high fever, lost her life as she was denied proper treatment
Mystery shrouds the incident as blood droplets were found inside the house. Also, Rs 5 lakh and 8 sovereigns of gold, kept in the cupboard, were found to be missing.
The deceased have been identified as Anju, 29, and her two children - son Kunju, 3 and daughter Chinnu, 6.
A young man had died outside the gate of a resort on Tuesday midnight.
Niveditha, a first standard student of the Government Lower Primary School, Cottonhill, met with the tragic end while she was having her afternoon snack at home on Sunday.
Murali, who worked as a senior music composer in All India Radio, had created several hit film songs in 1990s.
He had also served as Kerala Santhosh Trophy team's manager.
A high-level enquiry committee has been constituted to go into the cause of the fire.
This was the first visit by the CBI sleuths to Walayar after taking over the sensational case.