Six people, including a retired major general and a serving police inspector, have pleaded not guilty to plotting a coup to overthrow Nigeria's President Bola Tinubu.

The defendants appeared at the Federal High Court in the capital, Abuja, where they were ordered to remain in the custody of the Department of State Services (DSS), Nigeria's domestic spy agency.

A seventh person - a former governor and one-time oil minister, Timipre Sylva - has also been named as a conspirator, but court documents said he was still at large.

Rumours of the coup plot surfaced when the government abruptly cancelled a planned military parade to mark Nigeria's 65th Independence Anniversary on 1 October 2025.

At the time, officials cited security threats - but speculation quickly linked the cancellation to a possible coup plot.

The military initially denied the reports, but in January it announced that 16 officers were to be tried before a military court for attempting to oust the president.

Those to go on trial at the Federal High Court on charges of treason, terrorism and money laundering are civilians or retired military personnel alleged to have been part of the plot.

Sylva, who served as petroleum minister from 2019 to 2023 under former President Muhammadu Buhari and was also governor of the oil-rich southern Bayelsa state from 2007 to 2012, denied links to a coup plot after his house was ransacked by investigators last October.

An arrest warrant was issued for him the following month in a separate case launched by the country's anti-corruption agency.

At the time, his spokesman said the former minister was in the UK for a medical check-up and that the allegations were politically motivated.

The charges were filed by Attorney General Lateef Fagbemi on Tuesday. The six on trial are:

• Mohammed Ibrahim Gana, a retired major general
• Erasmus Ochegobia Victor, a retired Navy captain
• Ahmed Ibrahim, a police inspector
• Zekeri Umoru, an electrician working at the Presidential Villa
• Bukar Kashim Goni, a civilian
• Abdulkadir Sani, an Islamic cleric based in Zaria in Kaduna state.

The court scheduled 27 April for bail hearings.

During proceedings on Wednesday, defence lawyers complained of restricted access to their clients, claiming they had been unable to meet them since September 2025 - which would mean they had been arrested ahead of the Independence Day parade.

According to the charge sheet, the six defendants "conspired with one another to levy war against the state to overawe" the president.

The court papers suggest the coup plot was led by Col Mohammed Alhassan Ma'aji, who was arrested along with other alleged accomplices, and is due to go on trial at a military court.

Prosecutors also allege the defendants had prior knowledge of Col Ma'aji's "treasonable act", but failed to inform authorities.

The charges include the suppression of intelligence, with prosecutors alleging the defendants were intent on destabilising the state and had failed to disclose information that could have helped prevent terrorism.

Money-laundering allegations form a significant part of the case, with accusations that money changed hands linked to the financing of terrorism.

Under Nigerian law, treason attracts severe penalties, including life imprisonment.

Nigeria has experienced unbroken civilian rule since 1999.

This case is being closely watched as one of the most significant coup-related prosecutions in recent Nigerian history.

For months, the secrecy and unanswered questions over the alleged coup plot created a fertile ground for rumours, with speculation ranging from wider military involvement to claims of political vendettas.

Journalists and civil society groups repeatedly pressed for clarity, but access to information was limited.

The eventual arraignment of these six men has now brought the matter into open court.

However, questions remain about the scale of the alleged conspiracy and whether more suspects will be charged.