A CID official said the agency had arrested a third year ITI student from Kalyani yesterday. It was during his interrogation that he confessed the involvement of another youth, who was arrested today.
The duo, who are in their early 20s, were part of the racket involved in the leak, he said.
"Both were used as agents to deliver a set of questions to seven to eight students at a time and take money from them. The racket has been working as a chain," he said.
He has been remanded to police custody for eight days by Barasat Court and the youth arrested today would be produced in court tomorrow.
West Bengal government had cancelled ITI entrance tests and deferred it to July 5 after question papers were allegedly leaked. Chief Minister Mamata Banerjee had ordered a CID probe into the incident.