Executives from both carmakers in the Renault-Nissan alliance looked at least twice at legal ways to pay Chairman Carlos Ghosn undisclosed income through the partners' shared finances, documents seen by Reuters show.

The two efforts discussed in these documents were ultimately abandoned. However, the documents show for the first time that some discussions about compensating Ghosn out of the public eye were not confined to the Japanese carmaker, but also included Renault executives.

Ghosn's undisclosed Nissan income is at the center of allegations by Tokyo prosecutors against the alliance chairman, who has been charged with failing to disclose ¥5 billion in compensation for 2010 to 2015 that he had arranged to receive later.