The accused was brought to Badagara near here in the evening, where the main police investigation team is based, and his statement was recorded.
According to the police, it was Rajeesh who master-minded the murder of Chandrasekharan, a 51-year-old popular local leader in Onchiyam, who was killed May 4 while returning home on his motorcycle.
By now, the total number of people taken into custody in the case has touched 23, which includes nine activists of the Communist Party of India-Marxist (CPI-M).
The police said it was Rajeesh who planned the murder using a gang of seven hired killers. With his arrest, the police also expect to crack a few other murder cases.
A police official said Rajeesh, after Chandrasekharan's murder, left for Mumbai, where three Keralites provided him shelter. The police have arrested them.
Meanwhile, Kerala Chief Minister Oommen Chandy said no time frame could set to solve the case.
"This is because in the past it was the party (CPI-M) which handed over the accused whenever a political crime took place. But this time, it is going to be different and the real conspirators of the crime will be rounded up," Chandy told reporters in Kannur.