Hamza al-Mustapha is a former Nigerian Army major and intelligence officer who served as Chief Security Officer to General Sani Abacha, who was Nigeria's military head of state from 1993 until his sudden death on June 8, 1998.

He was born from Hausa family and educated in Nguru. He enrolled at the Nigerian Defence Academy in Kaduna and was commissioned into the Nigerian Army in 1983.

Al-Mustapha was trained as a military intelligence operative. He held various command posts in the Ministry of Internal Affairs, Security Group of the Directorate of Military Intelligence (SG-DMI), 82 Division and Army Headquarters; Ministry of Defence and The Presidency.

He was also involved in counter-intelligence activities and at least two investigations of coup attempts; which brought him to the attention of General Sani Abacha.

He also conducted operations in Chad, Liberia,  Bakassi , Gambia and Sierra Leone.

In his evidence before the Commission, Major Al-Mustapha emphasized that he had subscribed to an oath to protect the Head of State and his family as well as the Seat of Government.

General Sani Abacha died on 8 June 1998, following his death al-Mustapha assembled the military hierarchy in order to avoid a succession crisis. General Abdulsalam Abubakar emerged as head of state on 9 June 1998 and al-Mustapha was removed from office and subsequently arrested.

Following his arrest, al-Mustapha was first held and questioned during the Oputa panel, then accused of plotting at least four coups from prison, before being moved to the Kirikiri Maximum Security Prison, where he was tortured for over a year.

He won the presidential primary election conducted by the faction led by Kenneth Udeze, on June 9, 2022, in Abuja, thereby making him the presidential candidate of the Action Alliance party in the forthcoming elections.