A question mark hangs over somebody/something - Idioms by The Free Dictionary
a question mark hangs over somebody/something
question mark over
An element of doubt surrounding the quality, ability, or future of (something). If we don't secure new funding soon, there is going to be a question mark over the future of this agency. The recent media coverage of the scandal has left a question mark over whether he should remain CEO of the company.
a ˈquestion mark hangs over somebody/something,
there’s a ˈquestion mark (hanging) over somebody/something there is some doubt about somebody/something: A question mark hangs over the future of this club. ♢ There’s a question mark over his loyalty to the company.