Nine people were killed after there house were set ablaze in Birbhum's Bogtui village.
The CBI on Thursday arrested the e-rickshaw driver who allegedly transported the petrol that was used in setting ablaze the houses in Birbhum's Bogtui village, leading to the death of nine people, an official said.
Ritan Shiekh was arrested from his house in Bogtui in the early hours, he said.
"He was identified from the CCTV footage. Also, his name cropped up in statements given by other suspects arrested and witnesses," the CBI official told PTI.
Ritan went missing after the massacre, he said.
"He used to go into hiding during the day, and return home in the dead of the night," the official said.
The CBI was on the hunt for him, he said.
With this, the CBI has made six arrests in the case after taking over the probe from the West Bengal police on the direction of the Calcutta High Court. The agency has also taken custody of 22 persons earlier arrested by the police.
The CBI searched Ritan's house after his arrest, the official said.
Nine people died of burn injuries as their houses in Bogtui were allegedly firebombed after the murder of local TMC leader Bhadu Sheikh.