Dennis Itumbi has been Thursday arraigned in connection with the fake letter that claimed there was a plot to assassinate the Deputy President William Ruto.
The prosecution has asked the court to detain him for two weeks in order to complete investigations.
Mr Itumbi is accused of posting the letter in a WhatsApp group of the Tangatanga team allied to DP Ruto.
Mr Itumbi was arrested Wednesday while having lunch in Nairobi and will likely be charged with publishing alarming information.
Preliminary investigations on the letter, which purported that four Cabinet secretaries had met to plan about assassinating the DP, found that not only was it false, but was also written by people close to the DP.
Mr Itumbi, an ally of Dr Ruto, works at the DP's office, however, he is the State House digital director under the communications department.
Mr Itumbi is represented in court by lawyer Katwa Kigen.