Is Norm Coleman under federal investigation?

Last month, Sen. Norm Coleman (R-MN) came under fire in a lawsuit alleging that a donor, Nasser Kazeminy, used an insurance company that employs Coleman’s wife to pass money to Coleman illegally. After a watchdog group requested a federal investigation, Coleman’s office gave an “unequivocal ‘no‘” on whether he was being investigated. But TPM notes that now, Coleman’s office curiously won’t say whether he is under investigation:

Both the FBI and the ethics committee have declined to provide any information about whether they’re looking into Coleman. So we’ve been calling Coleman’s office to ask whether he’s heard from investigators. In fact, in the last few weeks, we’ve left at least ten detailed voicemail messages for Leroy Coleman, the senator’s Washington press secretary (and no relation) asking exactly that question. And we’ve received no response whatsoever.