They also alleged that a major was also involved in the killing.

Sumon, an IT specialist of Mirpur Primary Education Department, went missing on June 11 and the police recovered his slaughtered body bedside Dhaka-Chittagong highway at Chandina in Comilla the next day. Sumon was cremated in comilla after an autopsy as police mentioned him as a Hindu in the inquest report.

At a press conference in the city, Sumon's sister Nazma Sultana Usha said she and Sumon's wife Nawrin Zahan Mitu received calls on their cellphones on June 12 and 13 from an anonymous caller who told them to give up hope of getting back Sumon.

The caller also told Mitu that he has punished Sumon, a resident of Mirpur, as he (Sumon) has ruined the life of one of his dear ones, Usha added.

She also alleged that a major of Bangladesh Rifles might be behind the killing as he suspected that Sumon had a relationship with his wife, who is a friend of Usha.

The family members also said Sumon was cremated just to destroy the evidence of the murder.

Sumon's father Hamidur Rahman filed a case with Mirpur Police station on June 13. They also informed the Rapid Action Battalion (Rab) of their suspicion.

The family members came to know that Sumon was killed when Rab members called them to their office and showed pictures of slain Sumon on August 9.

Rab arrested two persons -- Shamsul Islam Matin and Ahsan Habib -- on August 8 from a village in Bogra. The arrestees also confessed that they and the major were involved in the killing, the family members said.