The DCI told the court that the matter is complex and requires more time to gather evidence, record statements, and pursue additional leads.
Prosecutors said investigations are still ongoing and that several other suspects linked to the alleged plot have not yet been arrested.
They warned that releasing the six suspects at this stage could jeopardise the case.
The prosecution further argued that there is a risk of interference with witnesses if the suspects are freed.
They told the court that some of the witnesses are yet to record their statements and could be intimidated or influenced if the suspects are released.
Investigators also cited the seriousness of the offence, noting that robbery with violence is a grave charge under Kenyan law and carries severe penalties upon conviction.
They maintained that keeping the suspects in custody would allow police to complete their inquiries without disruption.
The court heard that the suspects are currently being held at Capitol Hill Police Station, where they are undergoing processing as investigations continue.
Detectives are also analysing communication records and other material believed to be relevant to the case.
In addition, the DCI indicated that it is working to establish the full extent of the alleged plan, including how it was organised and whether there was any insider involvement.
The inclusion of KDF personnel among the suspects has added a sensitive dimension to the case, prompting closer scrutiny by investigators.
The prosecution urged the court to grant the 14-day detention period, arguing that it is necessary to ensure justice is served and that all those involved are brought to account.
The defence is expected to respond to the application, with lawyers likely to challenge the request for extended detention and push for the release of their clients on bail or bond.