Deutsche Bank’s American arm has come under scrutiny by New York state authorities for possible violations of trading rules. The bank’s asset management and brokerage unit is suspected of having helped investors make illegal after-hours trades in mutual funds. Investigators are also looking at a practice known as market timing, in which investors profit from rapid trades made in and out of various funds. New York state has issued the bank a subpoena asking it for documentation concerning its trading practices. Deutsche Bank has said it will cooperate fully with the probe, which the Reuters news agency has reported could lead to either criminal or civil charges. Deutsche Bank is the latest company to get caught up in the growing U.S. mutual fund scandal. The New York Attorney General’s office plans to bring charges against other companies and individuals in the coming weeks.