Dennis Itumbi, the State House digital director, will spend five more days in police custody.
Detectives on Thursday requested to detain Mr Itumbi as they investigate the source of a letter that alleged that several Cabinet Secretaries met in a Nairobi hotel to plan how to assassinate the Deputy President (DP) William Ruto.
Before the ruling was issued by the Nairobi court, Mr Itumbi told the magistrate that indeed there was a meeting held at Hotel La Mada whose agenda was allegedly to kill the DP.
Mr Itumbi said he had a video to prove his claim and requested the court to play it but the magistrate did not comment on the plea.
The State House communications official said he had given the same information to the Directorate of Criminal Investigations but the detectives seemed more interested in him attending court than his version of the truth.
The court then ordered him be detained at the Muthaiga Police Station to allow police investigate the "weighty issues" raised.
Several MPs who attended the court session to show support to Mr Itumbi said they want a Cabinet Secretary and Principal Secretary whom they did not name investigated over the alleged assassination plot.
Mr Itumbi is accused of posting the letter in a WhatsApp group of the Tangatanga team allied to Mr Ruto.
He was arrested on 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 works at the DP's office.
He is being represented in court by lawyer Katwa Kigen.