ICC Prosecutor Fatou Bensouda has said Uhuru Kenyatta's rise to the presidency was the key factor that led to the collapse of her case against him.
Bensouda said after Uhuru became President, witnesses refused to testify while the government stopped cooperating with the International Criminal Court.
She was reflecting on the collapse of the case against Uhuru in a documentary titled 'Kenya: A Guidebook to Impunity' hosted by human rights activist Maina Kiai.
Bensouda said the elevation of Uhuru and Deputy President William Ruto from ordinary politicians to the key principals negatively affected the case.
"After the elections and when they came to power, the case changed a lot. Now we are faced with a situation where the people we have already charged are now the leaders in Kenya," she said.
"Witnesses now find themselves in a situation where they have to give evidence against their President and Deputy President... their own leaders."
The case against Ruto and journalist Joshua Sang is still on.
Bensouda, who dropped Uhuru's case due to lack of sufficient evidence, said the government's cooperation also drastically changed when Uhuru became President.
"After 2013, the government pretended to cooperate with us. It is either we request for documents and the right documents are not given to us or we request for a list of documents and the full dossier is not given to us or they take a lot of time before they respond to any request for assistance or they give us the wrong documents or they don't give us at all," she said.
When dropping the case against Uhuru, Bensouda accused the Kenyan government of failing to cooperate with her office in her quest for evidence.
She had sought information on Uhuru's finances, property and telephone records but said the government refused to assist her.
The trial judges refused to sanction Kenya for this non-cooperation but Bensouda has appealed this decision.
A decision on the appeal is expected next month.
In the documentary posted online, Bensouda says her office had fulfilled its mandate but Uhuru and his allies intimidated and bribed witnesses.
She says she had anticipated witnesses in the Kenyan cases would be intimidated but was surprised by the high level with which it occurred.
"One of the strategies that we believe we need to adopt as a lesson is having an alternative source of evidence and not just relying on witnesses. We can then present a case without exposing as many people as possible as witnesses," Bensouda said.