Deputy President William Ruto has asked a court to order activist Boniface Mwangi to prove that he is corrupt.
The DP also wants the court to order Mr Mwangi to show proof that he participated in extra-judicial killings and disappearance of witnesses scheduled to testify in the crimes against humanity charges he faced at the International Criminal Court.
Through lawyer Kioko Kilukumi, Ruto labeled Mwangi a "rabble-rouser" whom he wants to state before court instances where he has grabbed public land or used his office to engage in corruption.
"The DP denies all claims made by Mwangi in his replying affidavit. Mwangi should be put to strict proof of how my client has engaged in corrupt land deals and that he had a leadership role in the design and implementation of a policy to eliminate ICC witnesses," said Mr Kilukumi.
In response to a counter-claim by Mr Mwangi that the DP defamed him, Kilukumi submitted that the activist has no reputation worth protecting.
"His reputation is that of a rabble-rouser camouflaged as a public-spirited individual. Such reputation is not worthy of protection by any court," said Kilukumi.
According to the lawyer, the findings of the ICC pre-trial chamber were merely procedural to determine if the trial could proceed and the judges never found Ruto guilty of committing any offence as alleged by the activist.
Mwangi had stated Ruto was not properly acquitted from the ICC, and that his case was only terminated due to witness coercion, killings and intrusion.
The activist further maintained the DP had been adversely mentioned in relation to corrupt dealings, among them alleged land grabbing and owning the Weston Hotel, which he claimed is built on public land.
The DP, however, defended his wealth against claims he had acquired the property through corrupt means, stating that his wealth was as a result of hard work.
"Whenever the DP acquired proprietary interests on immovable properties, he has been an innocent purchaser for value. In the event the properties were acquired through his companies then they were done in accordance with the law," said Kilukumi.
Ruto further defended his use of the word "hustler", saying that he is a "sufferer" who has struggled to make ends meet.
He further blamed unnamed political opponents as being behind Mwangi's hard-hitting response to his suit, adding that the statements were deliberately meant to continue defaming him.