Accused of genocide and of crimes against humanity, the former president, vice-president and secretary- general of the National Republican Movement for Democracy and Development (MRND), Mathieu Ngirumpatse, Edouard Karemera and Joseph Nzirorera, have all claimed their innocence.
The Rwandan linguist, Xavier Bangamwabo, had been called by Karemera, also a former minister of the interior.
In a decision posted on the Tribunal's website, the Chamber presided by Judge Dennis Byron, considered that after having read Bangamwabo's report, that it does not need his insight "to conclude on the guilt or innocence" of Karemera.
In 2007, the Chamber had already refused four experts proposed by the prosecution.
The testimony of experts would have undoubtedly exceedingly prolonged the proceedings in this case which has been going on since September 2005 and which will only be able to finish next year, according to the schedule of the presiding judge.
In addition, the Chamber must still come to a conclusion about a request for Karemera's "immediate release", who argues "the violation of his right to be tried without excessive delay".
The former Rwandan leader was arrested in Togo on 5 June 1998 and was transferred to the ICTR a month later.
In his motion, Dior Diagne, Karemera's main counsel, called for a court order from 3 March in which the Chamber recognized that the delay recorded in the course of the trial constitutes a violation of the right of a defendant to be tried without excessive delay.
"This is why the defence of Karemera requests that the Chamber revoke the indictment and to pronounce the definitive end of the proceedings" against the former minister.
Suspended since 28 May, the trial will resume on 22 June.
© Hirondelle News Agency