According to SaharaReporters, the governor's new wife is Gumsu Abacha, one of the daughters of the late General Sani Abacha, the former military Head of State.
The low-key wedding took place over the weekend at Mohammed Abacha's residence in Abuja.
Gumsu, 45, was previously married to Bayero Fadil Mohamadou, a Cameroonian multi-billionaire.
In 2019, the governor married Adama Ibrahim Gaidam, the daughter of his predecessor, just 24 hours after taking the oath of office.
Ummi Adama Gaidam, who was at the time studying in Saudi Arabia, became his third wife.
Buni was the APC's National Secretary when Gaidam showed interest in naming him as his successor.
His marriage to Gumsu, like his marriage to Ummi Adama, the daughter of his predecessor, Ibrahim Gaidam, is said to have been for political reasons.
Gumsu, the late former Head of State and Commander-in-Chief of the Armed Forces, and Mohamadou divorced in 2020.
They had been married for about 20 years before their marriage fell apart, and she has now found a new life in Buni's home.