The official, who spoke to the AP Thursday on condition of anonymity, said the fines came after a six-month investigation into ticket prices from Lagos' Murtala Muhammed International Airport to London's Heathrow Airport. The official said the carriers levied unreasonable fuel surplus prices on consumers.
The official spoke on condition of anonymity citing the sensitivity of the fines.
Officials with the two airlines declined to immediately comment.
The fines come as Nigeria is engaging in talks with the United Kingdom over a Nigerian carrier losing spots at Heathrow.
