Following the leakage of the General Science paper on Sunday night, the Assam Police registered a criminal case and the CID was handed over the investigation on Monday.
Director-General of Police Gyanendra Pratap Singh said a total of 22 persons have been detained from Guwahati, North Lakhimpur, Dhemaji, Sadiya, Dibrugarh and Tinsukia.
"Further lawful action as mandated by law is being taken against them. We remain committed to unearthing the network of people involved in leakage of the question paper and the conspirators," he tweeted.
Assam Police spokesperson Prasanta Kumar Bhuyan later told PTI that three persons from those called for questioning have been arrested in the paper leak case.
"They are all from the Government Deaf and Dumb School, Kahilipara in Guwahati. There were 42 packets of question papers meant for the school, but one was missing. This is a strong ground to arrest them," he said.
The arrested persons include the principal, a teacher and a casual employee of the school, said Bhuyan, the Inspector General of Police (Law and Order).
Read: Assam Class 10 science exam cancelled after question paper leak
On the people being interrogated, the senior official said, "Most of them are students of classes 11 and 12, while some teachers were also questioned. These students forwarded the question papers on WhatsApp. We are trying to find out the links and the source."
Bhuyan, however, said that police were not able to detect the source of the leak.
"Last night, we interrogated SEBA officials and they are likely to be called again. We are determined to crack this case as soon as possible," he added.
Earlier in the day, Education Minister Ranoj Pegu termed the arrest of teachers "unfortunate".
He had on Monday said, "There is no question of involvement of teachers. The papers are kept at police stations and sent to centres only on the morning of the exam day."
The minister also appealed to the public to share any information related to the case with the police.
The General Science question paper of the exam conducted by Board of Secondary Education, Assam (SEBA) was leaked on Sunday night and subsequently, the examination scheduled to take place on Monday was cancelled.
SEBA Controller of Examination NJ Sarmah had said that a handwritten model question paper of General Science of the HSLC (High School Leaving Certification) examination was available with some candidates and it also got circulated on social media.
According to a SEBA notification, the cancelled examination will now be held on March 30. Guwahati, March 14 (PTI)