If that amount swells to $30 million, the German flagship carrier will consider cutting capacity to Nigeria, the person said.
Global airlines association IATA has estimates that some $575 million of foreign airlines' revenues were trapped in Nigeria. U.S. carrier United and Spain's Iberia have stopped flying to Nigeria as a result.
A spokesman for Lufthansa said the carrier currently has no plans to cut flights to Nigeria and is including routes to the country in its winter schedule.
He declined to comment on details concerning Lufthansa's revenues in Nigeria.
Lufthansa currently flies to Nigeria from Frankfurt twice a day - once to Lagos and once to oil hub Port Harcourt via Nigerian capital Abuja.