Reggie Ranatunga had been granted bail in the same case, but Gampaha Magistrate Vijitha Seneviratne cancelled the bail following the death of the victim on October 29, a few days after he was assaulted allegedly by Ranatunga's men.
Reggie had got himself admitted to a private hospital on Thursday, but was taken into custody on Friday and shifted to the state-run Colombo National Hospital, police said.
Reggie Ranatunga was food minister in Chandrika Kumaratunga's cabinet and was the chief whip of the ruling party in the dissolved parliament.
Arjuna Ranatunga is also a candidate of the Peoples Alliance for Colombo district.
Lionel Rodrigo, a 35-year-old campaign worker of the opposition United National Party, had been set upon by a group allegedly led by Reggie Ranatunga, but the charge against the former minister then was that he had slapped the victim.
Subsequently, police said, Rodrigo was severely beaten up by the group.
Ranatunga had been taken into custody and released on bail the same day on a bond of Rs 50,000.
With the victim succumbing to his injuries, the case was treated as one of murder and demands for Ranatunga's arrest were raised.
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