Senior Communist Party of India-Marxist (CPI-M) leader P. Mohanan was arrested on Friday for his alleged involvement in the murder of former party colleague T.P. Chandrasekharan, police said.

In a major embarrassment for Kerala’s main opposition party, Mohanan, husband of firebrand CPI-M legislator K.K. Lathika, was taken into custody after police overtook his car and stopped it. He was travelling with party colleagues.

Mohanan is a senior CPI-M leader and also member of the Kozhikode district CPI-M committee. A large number of CPI-M activists, including top district leaders, assembled in front of the office where Mohanan was kept in custody.

With his arrest, the number of those in custody in the brutal murder of Chandrasekharan has crossed 50. Mohanan’s arrest had been on the cards since the alleged mastermind of the murder P.K.Kunhanandan surrendered before a court near Kozhikode last week.

Chandrasekharan, 51, a popular local leader in Onchiyam, was brutally killed on May 4 while returning home on his motorcycle. He was hacked 51 times by a group of assailants who came in an Innova car, according to police.

The entire investigation was proceeding like a pre-written script of the present Congress-led government, CPI-M legislator and Mohanan’s wife Lathika told reporters.

“The government wants to malign our party,” she said, adding that her husband was innocent.

CPI-M Kozhikode district secretary T.P. Ramakrishnan questioned the manner in which Mohanan was arrested.

“Police did not even give a notice to him,” he said.

The party – which has more than a dozen of its top leaders from Kannur and Kozhikode in custody for the murder – has said that it has no role in the killing.

On Friday, thousands of CPI-M workers will gather in Thiruvananthapuram to protest the witch-hunt of the party by the Oommen Chandy government.

State Home Minister T. Radhakrishnan told reporters after Mohanan’s arrest that the government had no role to play in the investigation.

“That’s the job of the police. We give neither direction nor advice on how the case should be handled,” he said.

K.K. Rema, Chandrasekharan’s wife, said: “His custody was just a matter of time… a few more will soon be taken into custody.”