David Parradang, was on Monday, quizzed for several hours by the Economic and Financial Crimes Commission (EFCC).
Commission’s spokesperson, Wilson Uwujaren, confirmed his interrogation.
He was summoned by the anti-graft agency over the alleged scam in the botched recruitment exercise that claimed some applicants.
As of press time, he was still under interrogation.
A commission source, however, said an administrative bail was likely.
Hundreds of million naira were collected from the thousands of applicants despite the limited space available for successful candidates.
The rowdy conduct of the recruitment exercise by the consultant contracted for it led to nationwide stampede that claimed many lives.
Though Parradang had continued as the CG under the administration of President Muhammadu Buhari, he was suspended following the report that a wanted ISIS terrorist acquired Nigerian visa illegally.
The presidency, however, said Parradang was suspended over the fatal recruitment exercise.
Despite being on suspension, Buhari had appointed Mr Martin Abeshi as Parradang’s replacement, sealing his fate on a possible return to his job.