Senior officers in the Nigerian military have reportedly reduced the use of regular phone calls following the ongoing investigation into an alleged plot to overthrow President Bola Tinubu’s administration.

Sources familiar with developments in the security sector made available to Politics Nigeria said some top officers now prefer encrypted messaging applications and face-to-face meetings for sensitive discussions.

The move is said to be driven by concerns that conventional telephone conversations are under close surveillance.

The development comes as criminal proceedings continue against military personnel and other suspects arrested over the alleged coup plot that came to public attention in late 2025.

According to security sources, the heightened monitoring followed the government’s decision to intensify intelligence gathering after uncovering what authorities described as a threat to the country’s democratic order. Several serving officers, a police officer and some civilians were later detained as part of the investigation.

The Federal Government has already filed charges against key suspects before the Federal High Court in Abuja. The defendants are facing allegations bordering on treason, terrorism and money laundering. They have, however, pleaded not guilty to the charges, while some military personnel are also expected to face a General Court Martial.

A retired senior military officer, who spoke on condition of anonymity, said intelligence monitoring within the armed forces is not entirely new. According to him, surveillance of senior officers has existed for years because of Nigeria’s history of military interventions in politics.

He argued that the latest investigation has only led to tighter security measures across the military hierarchy.

The retired officer also noted that concerns remain within security circles over the possibility of fresh attempts to destabilise the government, especially at a time when several African countries have experienced coups and attempted military takeovers in recent years.

He further claimed that there are pockets of dissatisfaction in some sections of the country over appointments into strategic security positions. However, he maintained that the present security leadership reflects a relatively broad national spread.

The source also pointed to internal grievances within the military, including controversies surrounding the attempted special promotion of President Tinubu’s aide-de-camp, Col. Nurudeen Yusuf. The proposed elevation reportedly generated criticism among some officers before the move was eventually stepped down.

However, efforts to obtain an official reaction from military authorities were unsuccessful as of the time of filing this report