The Central Bureau of Investigations on Thursday grilled Priyanka Todi and some of her relatives in connection with the mysterious death of her husband Rizwanur Rehman.

The CBI also questioned a student of the computer institute where Rizwanur used to teach. The student had called Rizwanur soon after the railway police found his body near the tracks at Dum Dum in Kolkata.

Three women officers of the agency interrogated Priyanka for the second time. They also questioned her mother Bimla Todi, her uncles Pradip Todi and Anil Sarogi and two of her aunts at the Todi residence in Kolkata.

Manoj Guha, a student of Arena Multimedia, called Rizwanur at 11 am on September 21, which was received by a GRP official.

Manoj was informed that the computer graphics teacher was dead. The student then called Rizwanur's family and broke the news.

"The CBI officials checked the call list, got my number and they summoned me. I told them everything I know," said Manoj.

"I called him because I wanted some clarification on the subject he teaches," he added.

Sadhan Singha, an officer in the Kolkata Police Detective Department and human rights activist Sudipto Sen were also questioned at the agency's make-shift office at Nizam Palace.

CBI Joint Director Arun Kumar, who is heading the team and is currently in Delhi, refused to divulge investigation details.

The agency had grilled Ashok Todi, the main accused in the case, for nearly 11 hours on Wednesday. The CBI also questioned former Bengal cricketer Snehashis Ganguly and Trinamool Congress MLA Javed Khan.