His movement has also been momentarily restricted until the outcome of the probe.
Onyema and his chief finance officer Ejiroghene Eghagha are facing the probe which followed the EFCC’s receipt of their indictment by the US Department of Justice (DoJ).
Six US agencies, including the immigration office, sources said, are handling the case in America.
According to the US government, the suspects are to face trial for alleged bank fraud, credit application fraud, money laundering, and aggravated identity theft.
An EFCC special panel is investigating the Nigerian component of the deals. Onyema, a source said, was grilled on Wednesday.
It was learnt that the fate of the Air Peace boss and Eghagha hangs on the Mutual Legal Assistance Treaty (MLAT) between Nigeria and the US. The treaty borders on the extradition of suspects to face trial in either country.
The source, who gave an update on the case, said: “Following his interaction with our detectives, it became imperative to restrict his movement to the country because we will need him from time to time.
“We have seized his passports for unfettered comprehensive investigation. And so far, he has cooperated with our team.
“During our interaction, he maintained his innocence. We have, however, made progress in our preliminary investigation”.
On the likelihood of extraditing Onyema to the US, the source added: “This depends on the MLAT between Nigeria and the US. For now, we are only investigating.
“The extradition process is within the purview of the Office of the Attorney-General of the Federation. You should not forget that the EFCC has to investigate, establish prima facie case and arraigning the suspects in court before any extradition application can be initiated.
“The US government knows what to do as far as the invocation of the MLAT is concerned. We are only fulfilling our own part of the collaboration with the relevant US agencies.”
The US agencies handling the case are the Drug Enforcement Administration, Internal Revenue Service Criminal Investigation, Immigration and Customs Enforcement’s Homeland Security Investigations, Federal Aviation Administration, Department of Commerce, and Department of Treasury.
Onyema and Eghagha were indicted on November 19 by the US Attorney’s Office, Northern District of Georgia in the DoJ.
Additionally, Onyema was charged with 27 counts of money laundering; while
Eghagha was accused of one count of aggravated identity theft.
A document by the US DoJ itemised the allegations against the suspects and described how the prosecution is being coordinated.
The document said: “The Drug Enforcement Administration, Internal Revenue Service Criminal Investigation, U.S. Immigration and Customs Enforcement’s Homeland Security Investigations, Federal Aviation Administration, Department of Commerce, and Department of Treasury are investigating this case.
“Assistant U.S. Attorney Garrett L. Bradford, Deputy Chief of the Narcotics and Dangerous Drugs Section and Lead Strike Force Attorney, Irina K. Dutcher, and Christopher J. Huber, Deputy Chief of the Complex Frauds Section, are prosecuting the case, with assistance from the Department of Justice’s Money Laundering and Asset Recovery Section and Office of International Affairs.
“This prosecution was brought as a part of the Department of Justice’s Organised Crime Drug Enforcement Task Forces (OCDETF) Co-located Strike Forces Initiative, which enables agents from different agencies to collaborate on intelligence-driven, multi-jurisdictional operations against a continuum of priority targets and their affiliate illicit financial networks.
“These prosecutor-led co-located Strike Forces capitalise on the synergy created through the long-term relationships that can be forged by agents, analysts, and prosecutors who remain together over time, and they epitomise the model that has proven most effective in combating organised crime.
” The specific mission of the Atlanta Strike Force is to disrupt and dismantle the most significant drug trafficking and money laundering organisations designated as Consolidated Priority Organisation Targets or Regional Priority Organisation Targets and their affiliates impacting the Atlanta metropolitan area and the Northern District of Georgia.”