They have released seven videos in total on their official Facebook page.
In the footages the suspects are seen following Avijit along with his wife Bonya at the book fair.
Masudur Rahman, deputy commissioner (media and publication) of DMP, confirmed the circulation of the videos to the Dhaka Tribune.
“We have have analyzed over two terabytes of 32 CCTV footage from the book fair and we have identified about six suspects,’ said the case supervising officer, Additional Deputy Commissioner of DB police, Rajib Al Masud.
DMP in it's official statement on Facebook said they are seeking people's help in identifying these six men.
The statement goes on to say that if anyone knowns who they are they should inform the DMP through Facebook messages or use the Counter Terrorism unit's “Hello CT” application.
In the first footage, a youth is seen following the couple while typing on his cellphone at 8:44pm. Another youth is seen moving away with a bag on shoulder while another rotund youth is seen around them wearing sunglasses.
In the second footage, Avijit and Bonya is seen coming out from book fair and these three youths can be seen around them talking to someone over the phone.
In another footage, one youth can been seen standing at the entrance to the book fair at 4:01pm wearing a shot panjabi and holding a cellphone. At the same time another youth is spotted entering the book fair on a bicycle.
Masruqure Rahman Khaqled, deputy commissioner of DB police said the rotund youth might be a resident of Old Dhaka and may not be technologically savvy.
We are getting some information regarding the suspects on the footage and we now need to be absolutely sure about them, he added.
Former Buet teacher Avijit Roy, also the founder of a secular blog called Mukto-Mona, was hacked to death by unidentified assailants on a pavement at TSC intersection on February 26 last year. His wife Rafida Ahmed Bonya was also injured in the attack.
Investigators say the attack was conducted by the banned militant outfit Ansarullah Bangla Team (ABT).
Police had arrested eight suspects in this case but were unable to get any major leads from them.
Visit www.dhakatribune.com to view the footages.