Friedrich Pleuger entered into a compensation business with the former ruler of Equatorial Guinea Macias Mguema. In this deal, local agricultural products from Equatorial Guinea were to be "exchanged" for medicines and vehicles from Germany. Specifically, it was "[2000 t] of cocoa from Equatorial Guinea [and] medical instruments, medicines, 6 Mercedes buses, 2 Mercedes Pullmann 600, 1 Mercedes 300 SEL, 1 Mercedes 280 SEL, 18 BMW motorcycles for the bodyguard, 2 Linotype typesetting machines and a vacuum cleaner [from Germany]". After the exchange of goods, the Agricultural Chamber of Equatorial Guinea posed as the seller and increased the price of the cocoa many times over. Since a friendship existed between the Pleuger couple and the family of Mguema, Irmgard Pleuger flew to Santa Isabel on December 9, 1970, to clarify the matter. She was provided with a "letter of protection" from the president, which, however, like her passport, was confiscated after her arrival and she was taken hostage. Since Irmgard Pleuger had heart problems, she was dependent on appropriate medication, which was not available in Santa Isabel. Therefore, Friedrich Pleuger asked the Geneva Red Cross for help, which brought the medication to Santa Isabel. During the entire kidnapping, the lawyer Christian L. Jarck, as Friedrich Pleuger's chief representative, negotiated with the government of Equatorial Guinea. Mguema demanded a seven-digit sum as a ransom. After Friedrich Pleuger had deposited a bank guarantee, Irmgard Pleuger was able to leave the country after delays by the government of Equatorial Guinea and arrived at Hamburg Airport on 17 January 1971. Together with the cost of the cocoa, the total ransom amounted to 6.1 million German Marks.
