50-year-old Onabanjo and Gafan, 52, are the Chief Executive Officers of Gaffa Oil and Gas Limited and Bugon Oil and Gas Limited, respectively.
The 2 were remanded shortly after their separate arraignment before Justice Mohammed Yunusa.
Arraigned and also jailed along with Onabanjo were Sani Idris, 34, and Bode Jonah, 39.
One Solomon Afolabi, 30; and Adesimisola Ogunsanya, 36, were also arraigned along with Gafan and remanded with him.
In the charge filed against Onabanjo and his co-accused, the police prosecutor, M.O. Omosun, alleged that the accused were, on August 15, 2015, caught with 16,000 litres of petrol loaded in several 50 litre jerrycans.
According to Omosun, the petroleum product which the accused dealt in belonged to PPMC and they did so without appropriate licence.
The petroleum product was said to be worth N1.55m.
The prosecutor said Onabanjo and others violated Section 3(6) of the Miscellaneous Offences Act Cap M17 of the Revised Edition, Law of the Federation of Nigeria, Act, 2007.
He added that they were liable to punishment under Section 17(b) of the same Act.
Onabanjo and others, however, pleaded not guilty.
In the case of Gafan, the prosecutor accused him and his alleged accomplices of illegally loading 25,000 litres of petrol from a vandalised pipeline into a Mercedes truck with number plate APP 04 QX.
According to the prosecutor, the accused loaded the said quantity of petrol, valued at N1.6m, without obtaining lawful permit from the Pipeline and Product Marketing Company, which owned the petroleum product.