A US firm has filed a $57 million lawsuit against Nigerian President Bola Tinubu, the Nigerian government, former aviation minister Femi Fani-Kayode, and DCI Group, a US public affairs and lobbying firm.
The case was filed in a federal court in Washington, DC.
The plaintiff, Karl Von Batten, alleges defamation and a conspiracy to kidnap and physically harm him.
Court records show the court has issued summonses to the defendants.
The $57 million claim includes $36 million sought from Tinubu and the Nigerian government, $3 million from Fani-Kayode and $18 million from DCI Group.
Fani-Kayode has rejected the allegations.
Von Batten heads a US lobbying firm that has worked for former Nigerian vice-president Atiku Abubakar, Tinubu's political rival.
His firm has been pushing in the US for the release of FBI and DEA records concerning past allegations involving Tinubu.
The claims have not been proven in court.