Ghosn was detained on his private jet at Haneda Airport, which serves Tokyo, after a whistleblower at Nissan made allegations that he had underreported compensation to the Japanese government. Another executive, Greg Kelly, whom authorities described as the architect of the scheme, was also arrested. Neither Ghosn nor Kelly could be reached for comment. After a monthslong internal inquiry, Nissan said it was planning to strip Ghosn of his position as chairman when its board meets Thursday. Ratings agencies warned of the scandal's financial impact. Standard & Poor's said it could downgrade Nissan's credit rating over the allegations, a move that would raise the company's borrowing costs. Nissan's profitability could "weaken substantially" in the fiscal years 2018 and 2019 if it turned out that Ghosn's alleged misconduct had hurt sales or the company's alliance with Renault and Mitsubishi, S&P said in a statement.