Prior to the in camera testimony, the Defence and the Prosecution had been convened for a one hour meeting in the judges' office.
It was not disclosed on Tuesday whether other "character witnesses" would be admitted before the court is slated to announce its verdict, on November 05.
Bagaragaza, a close friend of the former Rwandan President Juvénal Habyarimana, pleaded guilty of ‘'complicity to commit genocide'' on September 17.
His is the ninth guilty plea before the ICTR, the result of complex negotiations between the defendant and the Office of the Prosecutor.
Bagaragaza had hoped to be tried in Europe in exchange for his collaboration with the Prosecution. Having taken the stand against other defendants, including Protais Zigiranyirazo, Habyarimana's brother-in-law, Bagaragaza, who voiced fears for his safety, had been transferred to, and detained in, The Hague.
The Prosecutor had committed himself to a trial in a European country. But initial attempts in Norway, and then in The Netherlands, failed. In May 2008, the defendant was sent back to Arusha.
Bagaragaza nonetheless stuck to his guilty plea which permits the ICTR to expedite his trial. In return, he hopes for clemency.
With the notable exception of the former Rwandan Prime Minister Jean Kambanda, who was sentenced to life in prison, all defendants admitting to their responsibility in the 1994 genocide have benefited from substantially reduced terms.
© Hirondelle News Agency