Adoke was detained by the anti-graft agency on Thursday after he was handed over to the EFCC by international police organisation, INTERPOL.
He was taken into custody by the EFCC for his alleged involvement in the granting of the Oil Prospecting License (OPL) 245 to Shell and ENI.
This comes shortly after the former AGF returned to the country from Dubai in company with INTERPOL officers aboard Emirates Airlines Flight 785.
The aircraft is said to have departed the Emirati commercial capital at about 8am Nigerian time and touched down at the Nnamdi Azikiwe International Airport in Abuja after about eight hours later.
Adoke was, thereafter, whisked away to the INTERPOL office in Abuja after which he was transferred to the EFCC office also in the nation’s capital.
The former AGF is facing charges bordering on alleged abuse of office and money laundering with respect to the granting of the Oil Prospecting License (OPL) 245 to Shell and ENI filed against him and four others by the EFCC on behalf of the Nigerian Government.
The administration of former President Olusegun Obasanjo had revoked the OPL 245, which the late General Sani Abacha granted Mr Dan Etete who was his Petroleum Minister, and reassigned it to Shell Nigeria Exploration and Production Company.
Malabu Oil and Gas was, however, said to have reclaimed the oil block in 2006 through the court while Shell rejected and challenged the decision.
The EFCC claimed that fraudulent settlement and resolution ensued, allowing Shell and Eni to buy the oil block from Malabu in the sum of $1.1billion.
Investigations into the deal, according to the anti-graft agency, revealed crimes that bordered on conspiracy, forgery of bank documents, bribery, corruption and money laundering to the tune of over $1.2 billion.
Following its inability to produce the defendants in court, the anti-graft agency approached a Federal Capital Territory High Court in Abuja on April 17 to secure a warrant of arrest against them.
The court granted the request by the EFCC, leading to Adoke’s arrest by the police in Dubai in November.
But in a statement on Thursday, lawyer to Mr Adoke and Senior Advocate of Nigeria, Mike Ozekhome, said his client had been released and was already on his way to Nigeria.
Ozekhome insisted that the former AGF was not extradited but was set free by the police in Dubai after he said he wanted to go home and “solve his problems back at home”.
“Adoke is not extradited by the Nigerian government because there is no reason for that … he is innocent of the allegations against him. Adoke has not done anything wrong,” he said.