She said the president's indifferent attitude towards previous scandals will have to change.
The ex minister said the events that led to the return of Maina as the director of the Ministry of Interior's human resource department despite the pending corruption charges against him was facilitated by the dysfunction that exists between institutions responsible for pushing the president's anti-corruption agenda.
Pointing out the well-publicised isolation between anti-graft agency, the Economic and Financial Crimes Commission (EFCC) and the office of the Attorney-General of the Federation, Abubakar Malami, Ezekwesili said the best way for President Buhari to approach the situation is by full disclosure to the public.
She pointed out that the president's indifferent attitude towards previous scandals will have to change if he wants Nigerians to believe in his anti-corruption agenda.
To restore public confidence, she also advised the president to address other pending corruption scandals involving suspended Secretary to the Government of the Federation (SGF), Babachir Lawal, and the Director of the National Intelligence Agency (NIA), Ayodele Oke.
Taking to her Twitter account (@obyezeks), on Wednesday, October 25, 2017, the former minister posted, "There is no redeeming prospect in the colossal mess made by officials of the Federal Government in the MainaGate. But, at least start with full disclosure.
"MainaGate is the most lethal blow yet to a struggling anti-corruption agenda that had the Economic and Financial Crimes Commission (EFCC) increasingly isolated by the Attorney-General of the Federation.
"Something is fundamentally broken in governance and MainaGate is a mere symptom. President Muhammadu Buhari's usual aloofness on such matters won't work.
"MainaGate is one scandal too many for President Muhammadu Buhari's administration. The time has come for the President to own these scandals and act.
"If President Buhari took public confidence building measures on MainaGate, SGFGate, NIAGate, he may yet revive faith in his agenda."
Maina was recalled and promoted after he had been dismissed by the Federal Civil Service Commission in 2013 following a recommendation by the Office of the Head of Service.
In 2015, he was charged alongside former Head of Service, Steve Oronsaye, Osarenkhoe Afe and Fredrick Hamilton Global Services Limited before a Federal High Court on a 24-count charge bordering on procurement fraud and obtaining by false pretence through the award of fraudulent biometric contracts.
After he was declared wanted over an alleged N2 billion pension fraud, he fled abroad to the United Arab Emirates (UAE), evading the capture of the EFCC.
Minister of Interior, Abdulrahman Dambazau, Head of Service, Mrs Winifred Oyo-Ita, and AGF Malami have been reported to be instrumental to the process of Maina's recall.
On Monday, October 23, after his reinstatement drew public condemnation, President Muhammadu Buhari ordered Maina's 'disengagement' and ordered a full investigation into the circumstances of his recall.
On Tuesday, October 24, the Senate and House of Representatives also set up separate ad-hoc committees to investigate the issue.