Law enforcers have found evidence that the hand-written question paper of Dhaka University's “Gha” unit admission test, which was leaked around 45 minutes prior to the exam, was circulated from two admission information centres in Bogura to an applicant's guardian.

Six people, including the admission seeker and his father, were arrested on Saturday in connection with the incident. Each of them was taken on a two-day remand yesterday.

After scrutinising one of the admission seeker's mobile phone, investigators found images containing hand-written questions in the applicant's Facebook messenger to be identical to the original ones.

“The questions came at 9:17am on Friday,” Molla Nazrul Islam, special superintendent of Criminal Investigation Department (CID) of police, told The Daily Star.

On Saturday, DU's Chief Security Officer SM Kamrul Ahsan filed a case with Shahbagh Police Station accusing the six and some others, under sections 22 and 33 of the Digital Security Act, and the Public Examination Act. It was mentioned in the case statement that the questions were leaked through digital devices prior to the exam.

The arrestees are – Insan Ali Rocky, 19, the admission seeker; his father Jahidul Islam, 45; Mostakim Hossain, 20; Sadman Salid, 21; Tanvir Ahmed, 21; and Abu Taleb, 19; all hailing from Bogura.

On information, police first arrested Rocky from Doyel Chattar area on Saturday. After investigators scrutinised his mobile phone and found that the question paper was sent from his father's phone, police also arrested his father Jahidul.

During primary interrogation, Jahidul told the investigators that he got the question paper from Laheduzzaman Limon, owner of “Google Admission and Information Centre”, and Sabbir Hossain Rana, owner of “Rahema Computer Centre”, in Jaleshwaritala of Bogura, in exchange of Tk 3 lakh, according to the case statement. However, from where Limon and Rana managed to get the questions is still unknown.

Based on their information, police arrested Mostakim, Sadman, Tanvir and Taleb from a Sylhet-bound bus.

Jahidul said the four are cohorts of Limon and Rana and they were involved in leaking questions of DU's “Gha” unit admission test through digital devices.

Police said they were now looking for the two kingpins of the two admission information centers -- Limon and Rana.

Allegations of question paper leak in "Gha" Unit admission test also surfaced last year after e-mails containing questions of the English part of the exam were sent to some admission seekers around eight hours before the exam.

Like the previous year, the university authorities were unclear regarding the question leak and gave the responsibility to a probe body formed on Saturday. The probe committee was asked to submit a report within 48 hours.

"The probe body formed over the incident is now looking into the allegation to verify whether it was a question paper leak or digital forgery. We will be able to say it after the completion of the investigation," DU Proctor Prof AKM Golam Rabbani told The Daily Star.

The DU probe body yesterday called three journalists separately to know about the incident of question leak. One of the journalists present there, wishing anonymity, said that they have requested the authorities to cancel the test or revoke the admission of those found to be involved.

On Friday, the admission test of DU's "Gha" Unit for the 2018-2019 Session was held, where a total of 95,341 candidates vied for 1,615 seats. Some 59 applicants contested against each seat under the unit.

The Daily Star, on Friday, obtained a total of 14 images of a handwritten script containing multiple-choice questions (MCQ) with answers at around 10:31am.

After scrutinising the images and the original question paper given at the exam halls, this correspondent found that 72 MCQs in the leaked images matched the original script.

A screenshot also validated that the images were supplied to some admission seekers at around 9:17am via Facebook Messenger and WhatsApp.

After getting the leaked question paper, a campus-based journalist informed an assistant proctor of the university midway through the exam, asking him to take immediate steps.

Of the total 100 MCQs, 19 MCQs of the Bangla part, 17 from English and 36 from general knowledge matched with the leaked question paper.