In a tweet, the Aviation Minister, Hadi Sirika, said a UK company “was given approval for humanitarian operations but regrettably we caught them conducting commercial flights.”

“The craft is impounded, crew being interrogated. There shall be maximum penalty,” he added.

Nigeria has banned passenger flights into the country for weeks. This ban excludes ones to evacuate citizens of other countries or repatriate Nigerian citizens. Flights for essential services, such as food and items for humanitarian use are also allowed.

The ban will remain in place until at least June 4, 2020.

An Aviation Ministry spokesperson, James Oduadu, told Reuters later in a telephone interview that the plane was operated by a company called FlairJet.

FlairJet, a British private charter company that is an affiliate of Flexjet. In a statement, the company said the matter was an "evolving situation".

"We are continuing to respectfully work with the Nigerian authorities to resolve this situation," it said.