NEW DELHI, March 29 (Xinhua) -- Indian police Thursday detained the owner of a tutorial center in Delhi in connection with the leak of question papers that led to the cancellation of 10th standard mathematics and 12th standard economics board examinations.

"Vicky, the owner of Vidya Coaching Center in Delhi, has been taken into police custody for questioning. He is one of the main suspects in the question paper leak. His tutorial center is suspected to be the origin of the leaks," a police official told the media.

"Vicky, during preliminary interrogation, has named two schools behind the leak. We have already questioned 25 people, mostly students, in connection with the exam paper leak, after the same were circulated on social media platforms like WhatsApp," he added.

Meanwhile, students in Delhi have been holding massive protests, demanding that the state-run Central Board of Secondary Education hold a re-examination for all papers, instead of just the two papers.

A special investigation team has been formed to probe the leaks.

Indian Prime Minister Narendra Modi Wednesday expressed his unhappiness over the leak of the exam papers and asked the Human Resource Development (HRD) Ministry to take strict action.

"We have taken serious note of the issue. It looks like some sort of gang is behind this. The prime minister has asked us to take strict action against all involved," HRD Minister Prakash Javadekar has said.