A review ordered by the International Criminal Court's chief prosecutor into the failed case against Kenyan President Uhuru Kenyatta put the blame Tuesday on the "autocratic" leadership of her predecessor.
The probe conducted by three independent experts said then prosecutor Luis Moreno-Ocampo pushed ahead with the Kenya case despite problems with evidence and accused him of "angry, threatening" reactions when staff disagreed with him.
The war crimes court based in The Hague had put Kenyatta and his vice president William Ruto on trial for orchestrating political violence that left over 1,200 dead after elections in 2007.
Charges were dropped against both leaders in 2014 by current ICC chief prosecutor Fatou Bensouda, who at the time blamed a relentless campaign of victim intimidation.
Argentinian Moreno-Ocampo's "leadership could best be categorized as autocratic," said the review by experts in prosecuting war crimes and crimes against humanity.
He created a culture that the ICC "must go forward with the Kenya cases... regardless of the evidentiary insufficiencies, and that any other view was disloyal."
A statement by Moreno-Ocampo also released by the ICC said the probe had not interviewed him and contained "unfounded personal attacks".
The review also found the ICC had underestimated the ability of "powerful, sophisticated, well-funded and organised" suspects to undermine the prosecution's evidence.
Staff at the ICC prosecutor's office at the time were furthermore not up to the job, the review said, adding that there were "too many staff positions being filled by individuals who did not have the requisite experience and skill sets."
Bensouda, who released the report on Tuesday, said her office had learned lessons from the episode. The report said working practices had improved since the Gambian took over in 2012.
The ICC and the prosecutor's office in particular have faced criticism after a number of cases including former Ivorian president Laurent Gbabo collapsed. It has also come under fire for mainly targeting African suspects.
Set up in 2002, the ICC is the world's only permanent, independent tribunal that deals with the worst crimes including genocide, war crimes and crimes against humanity.