Last week Mr Ghosn resigned as chairman and chief executive of French car maker Renault, which is part of an alliance with Nissan and Mitsubishi. Combined, the three companies form the world's largest car business, with the tie-up allowing them to share costs such as R&D and production. A fortnight ago, Nissan and Mitsubishi also claimed that Mr Ghosn received €7.8m in "improper payments" from a joint venture between the two car makers based in the Netherlands. Mr Ghosn became a celebrity businessman in Japan after dragging Nissan back from the brink of bankruptcy.