The CBI is understood to have come to the conclusion that Rizwanaur Rehman, a computer graphics teacher of Kolkata, had committed suicide and is likely to book two members of the Todi family and two police officers alleged abetment.

The investigating agency, which was directed by the Calcutta High Court to probe the death, is expected to apprise the court next week of its findings and file a report in this regard, sources said.

In the wake of a raging controversy over the alleged role of policemen in collusion with the businessman' family, the issue was taken up in the Calcutta High Court, which had directed the CBI to go into the circumstances of the unnatural death of the young man, whose body was found on the rail tracks near Dum Dum on September 21 last year.

CBI sources said the agency had retrieved the last suicide note from the computer recovered from the kin of Rehman who died under mysterious circumstances after his wife was taken back to her maternal home.

The CBI gathered this data from the computer which was recovered from the house of Rehman's maternal aunt, who after his death on September 21 had deleted the letter, the CBI sources said.

They said the letter was retrieved at the forensic laboratory in which Rehman had stated the condition of his mind and non cooperation from the Todi family in allowing him to meet his wife, Priyanka.

According to the CBI probe, a "close" relative of Priyanka, whom the victim had married, had  allegedly used pressure tactics to drive Rehman to such a stage where he took the extreme step of committing suicide.