Okoi's comments came as a new book on Boko Haram highlights the group's many sources of funding. In Boko Haram: Nigeria’s Islamist Insurgency, Virginia Comolli explains that the sect had benefited from many sources – from northern officials to Internet scams.
"During the early stages of Boko Haram [around 2002] there had been a number of officials and northern businessmen who were involved in providing support," she said in an interview. "It is also possible that in the early days a number of local politicians would have hired the early Boko Haram members as their political enforcers, basically local thugs used to intimidate political opponents."
This practice is common in sub-Saharan Africa where youths, including impoverished street children and Koranic school students, have been used as "militias" by political parties and security forces.
Criminal activities, including bank robberies, extortion and racketeering, have generated revenues for Boko Haram. "We’re not talking about involvement in international organised criminal networks," cautioned the International Institute for Strategic Studies analyst, "but they were important in keeping the group afloat."
Even within Islamist ranks, religious scholars have debated whether illicit (haram) practices are compatible with Islam and shariah [Islamic law]. "Unfortunately, what we’ve seen – not only in the case of Boko Haram but also in the case of other violent Islamist groups – is that practices that are clearly haram under Islam are being condoned, used and justified because they are helping the groups achieve their ultimate goal."
Boko Haram, which now calls itself the Islamic State's West African Province, has called for the establishment of an Islamic caliphate and the overthrow of Nigeria because it is a secular republic.
Boko Haram has also reportedly been funded by like-minded groups like Al-Qaeda in the Islamic Maghreb (AQIM), which allied itself to armed Tuareg groups to destabilise northern Mali in 2012. AQIM are said to have trained Boko Haram members in bomb-making and kidnapping for ransom – not a Boko Haram staple when the Islamist sect started operating in Nigeria’s north-east.
"There have been several reports indicating that disputes within Boko Haram had taken place over how ransom money would be split," Comolli said. "We’re talking about fairly large sums of money that would have allowed the funding of several operations."
In her book, Comolli writes that the leader of Boko Haram splinter group Ansaru, Kalid al-Barnawi, took a sizeable cut (228,000 euros) from ransom payments that western nations had made to AQIM.
Boko Haram controls large swathes of the road from Maiduguri, the Borno State capital, to Lake Chad, where Nigeria joins Niger, Chad and Cameroon, a well-known trafficking route. Petrol and diesel, textiles and fish, cigarettes and counterfeit drugs can be found along the way.
"Boko Haram is not directly involved in the trade," said Sasha Jesperson, a London-based researcher with Royal United Services Institute for Defence and Security Studies. "They are not conducting the trafficking themselves but it’s likely that they are taxing the trade when it passes through the areas that they have control over."
The sect may also be involved in human trafficking. "If they have women and girls who have been kidnapped they will [potentially] sell them on to human traffickers," explained Jesperson, not ruling out the possibility that some of the more than 200 Chibok schoolgirls kidnapped in 2014 may have been sold to a human trafficking ring.
The UN Office on Drugs and Crime (UNODC) believes the Islamist insurgency has benefited from drug trafficking. "Boko Haram in Nigeria has been involved, directly or through levying taxes, in the illicit trafficking of drugs and natural resources," UNODC Executive Director Yuri Fedotov told an international meeting in Doha in April. The agency launched Monday a project to support "the fight against trafficking in persons in Nigeria" with Japanese backing.
Internet scams have also been a source of Boko Haram funding. The Inter-Governmental Action Group Against Money-Laundering in West Africa, an Ecowas regional bloc agency, has documented how Boko Haram contacts westerners in an apparent attempt to develop a romantic relationship. Victims were asked to send compromising pictures and then black-mailed.
To investigate suspicious financial transactions Nigeria established a Financial Intelligence Unit in 2004 and an Anti-Money Laundering and Combating of Terrorism Regulation in 2009.
"We have put in place the necessary legal and regulatory frameworks that would make it difficult for terrorist groups and criminal networks to launder money obtained through cross-border criminal activities," Nigerian Foreign Minister Aminu Wali told the UN Security Council in December 2014. "However, there is no doubt that this is an ongoing war."
Follow Michel Arseneault on Twitter @miko75011