Detectives are looking for Rajshahi University English department student Shariful Islam, who is a leader of radical group Islami Chhatra Shibir, for his direct involvement in the murder of his teacher Prof AFM Rezaul Karim Siddique on April 23.

But the justice seekers have expressed concern over a fair probe into the gruesome killing as Shibir – unpopular for its brutality – is the most influential political group in Rajshahi region, especially the university campus.

Soon after the murder, Islamic State claimed responsibility for the murder terming the teacher an atheist. But the police have found that it was an act of the university’s Shibir men. They think that the Shibir leaders have established connection with the IS leaders in Syria through Jamaat men staying in Bangladesh, the UK and the US.

On the other hand, banned group Ansarullah Bangla Team or Ansar Al Islam, formed with ex-Shibir and Hizb-ut Tahrir men, has established network with al-Qaeda.

The detectives earlier said that Shibir and banned militant outfit Hizb-ut Tahrir have been leading the combined platform of militants since 2013 as all the groups want to establish Shariah law in the country.

“Police are confirmed that the teacher was killed over ideological differences. We will be able to learn about the motive of the murder once we can arrest Shariful,” Rajshahi Additional Commissioner Sarder Tamij Uddin Ahmed told reporters on Monday.

Police have so far arrested two people in connection with the murder of Prof Rezaul who was a music enthusiast and writer. The arrestees are Raihanul Islam, the imam of Baghmara’s Dorgamaria village mosque, and Shibir member Khairul Islam of Rajshahi. They were put on four-day remand each on Monday.

Police earlier questioned three more people including Shariful’s father Abdul Hakim and brother Ariful Islam. They claimed that Shariful had not contacted with the family for the last two years.

Another remanded is Hafizur Rahman, a second year student of public administration department, of Rajshahi University.

Doubts over fair probe

After the killing of RU sociology department teacher and Baul researcher Prof AKM Shafiul Islam on November 15, 2014, Rajshahi police found the involvement of Shibir men in the murder. They also arrested some activists, but released them later following the directives of the government highups.

A few days later, elite force Rapid Action Battalion came up with a new theory: Prof Shafiul was killed over personal conflict with a female accounts officer of the university. The officer’s husband, who is a Jubo Dal leader, and his friends killed Prof Shafiul, RAB claimed.

But newspapers in Dhaka reported that the female officer did not even know Prof Shafiul. It shows the influence of Shibir in Rajshahi, which is also a den of outlawed militant group JMB.

Shibir men earlier killed two other teachers and some students of the university in fierce attacks. They are widely accused of severing tendons of many students at RU and other educational institutions including Chittagong University.