Prosecutors submitted a phone recording to International Crimes Tribunal-2 on 6 August during a second day of closing arguments in a crimes-against-humanity case against seven accused leaders.
The panel was led by Justice Nazrul Islam Chowdhury.
The prosecution alleged that Obaidul Quader called student-wing leaders Saddam Hossain and Wali Asif Inan on 11 July 2024 and instructed them to attack student protesters.
In the recording presented in court, a voice identified by the prosecution as Quader asks why the protesters were not being beaten and why they were being allowed to grow in number.
The recording includes a response attributed to Saddam saying police had prohibited a confrontation with the protesters.
The prosecution said the call concerned an estimated 3,000 students who were taking part in a programme and planned to announce their next steps at a news conference that evening.
Prosecutors argued that violence during the July-August uprising was planned, organised and coordinated by central political leaders, law-enforcement agencies and affiliated organisations.
They further alleged that the accused gave instructions, made inciting statements and planned violence to suppress the movement, contributing to killings, attempted killings and widespread violence.
The other accused are A F M Bahauddin Nasim, Mohammad Ali Arafat, Sheikh Fazle Shams Parash, Mainul Hossain Khan Nikhil, Saddam Hossain and Wali Asif Inan.
All seven accused were described as fugitives.
Testimony from 28 witnesses, including the investigating officer, concluded on 2 August, after the tribunal took cognisance of formal charges on 18 December 2025 and ordered the trial to begin on 22 January.
The evidence set does not include a defence response, a ruling on the recording's authenticity or admissibility, or a verdict.