The Central Bureau of Investigation on Monday interrogated four persons in connection with the death of Rizwanur Rehman.

Prime accused Ashoke Todi's brother Pradip Todi, his uncle Anil Sarogi, who is alleged to have been an eyewitness to the death of the computer graphics teacher, and his former girlfriend were among those questioned.

A three-member CBI team went to the spot where Rizwanur's body was found on September 21 and zeroed in on three persons stated to be present at the time of the incident. The sleuths also picked up a person identified as Ashis Das and interrogated him at the CBI office at Nizam Palace.

"We have videographed everything and we will examine it later. We cannot divulge details but we can say the investigation is moving in the right direction and in good pace," CBI Joint Director Arun Kumar, who led the team, said.

Asked whether the CBI is satisfied with the postmortem report, Kumar said, "The post mortem report has been taken by our forensic experts. Our expert has taken it to Delhi for close examination. Until he gives his report, we cannot say anything."

Two women officials went to Rizwanur's former girlfriend Pompi Banerjee's house and interrogated her.

The team interrogated Ashoke Todi's brother Pradip Todi and Anil Sarogi, his uncle who took Rizwanur's wife Priyanka to her father's home from the Kolkata police department's headquarters.

"We have tried to know from them the sequence of events and more importantly we wanted to cross check the whole sequence with our findings," said Kumar.

Asked whether the CBI would consider the findings of West Bengal CID, Kumar said, "We don't want to be impressed by anything and we will do all our investigation independently."

Rizwanur, after marrying Priyanka, the daughter of affluent businessman Ashok Todi on August 18 against the wishes of his father in-law, was found dead on September 21.

Former city police Commissioner Prasun Mukherjee had on September 23 admitted having summoned the couple to the police headquarters on September 1, 4 and 8 when two officers of the rank of deputy commissioner tried to persuade Priyanka to return to her parents.

The state government, which ordered a Criminal Investigation Department probe into the incident on September 24, later ordered a judicial inquiry just after three days as Rizwanur's death caused a national outcry.

The state government had removed five police officers, including police Commissioner Prasun Mukherjee and two deputy commissioners on October 17, a day after the Calcutta high court ordered a CBI probe after Rizwanur's family filed a petition.