Challenges Obasanjo to public debate …Says Yoruba leaders, except Oba Tejuosho, deceived MKO By Ikenna Asomba LAGOS—Former Chief Security Officer to the late Head of State, Gen. Sani Abacha, Major Hamza Al-Mustapha, yesterday, said he would soon reveal how his boss and the acclaimed winner of June 12, 1993 presidential election, Chief Bashorun MKO Abiola, died. Disclosing that Abacha and Abiola’s deaths were from same source, Al-Mustapha said he would make the comprehensive revelation in his new book, Mustapha’s Memoirs, which, according to him, is still in the works. Al-Mustapha, who addressed journalists in Lagos yesterday, on a number of issues relating to his 15-year travails in detention, said Abiola and Abacha were very good friends before some fifth columnists caused disaffection between them. He said: “For instance, when Chief MKO Abiola was in prison, many notable Nigerians visited him. They will visit him in the morning, and when they come back to the Villa in the