Arrested Trinamool Congress leader Mohammad Iqbal, a key accused in the murder of a police officer in Kolkata on February 12, was on Saturday brought to Kolkata from Bihar by the police under heavy security, officials said.
Iqbal was brought from Dehri-on-Sone in Bihar to Howrah by train and taken to the Criminal Investigation Department (CID) headquarters Bhavani Bhavan, on a two-day transit remand, West Bengal police's CID sources said.
He is likely to be produced in a court later in the day.
On the run after the February 12 incident, Iqbal claimed that he was asked by his party leaders to evade arrest.
Iqbal, who has been charged with rioting and attempt to murder, was arrested Thursday night from Dehri-on-Sone in Bihar, 23 days after special branch officer Tapas Chowdhury was shot dead in broad daylight in the city's Garden Reach area during a clash between student activists.
Chowdhury was killed while he was trying to control clashing groups of students with affiliation to the Trinamool Congress and Congress at the Harimohan Ghosh College.
The Trinamool councillor and chief of the borough committee was seen at the spot of the incident, threatening a policeman and mobilising his supporters.
Video footage aired by television channels showed Iqbal standing beside Sheikh Subhaan, the man who was caught on TV firing the bullet that allegedly killed the policeman.
The violence had erupted over the issue of picking up nomination forms for the students' union polls.
Twelve people, including Subhaan, an aide of Iqbal, are currently behind bars for their role in the violence.