The elite police unit claimed that he was the 'mastermind' of the murder but did not disclose any other details.
Chowdhury, a former brigadier general, was found murdered in his home at the Defence Officers' Housing Society (DOHS) in the capital's Mohakhali on Oct 3.
The 76-year-old, who hailed from Sylhet's Golapganj, retired from the army in 1992.
His son had found him unconscious and rushed to the Combined Military Hospital, where the doctors declared him dead.
Police said there was black bruise on Waji Ahmed's throat and wound marks on the chest and leg.
Autopsy reports by the Dhaka Medical College Hospital concluded that he was strangled to death.
His nephew Reshad Ahmed Chowdhury started a case accusing the house help 'Abdullah'.
According to the case details, the youth could not be traced since the incident and TV, mobile phone and laptop were missing from the home.