The most common and most likely answer to this crossword clue is the 10 letter word CHALLENGED
I've seen this crossword clue in The Daily Telegraph
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More clues leading to the result CHALLENGED
Buddy explains!

The straight part
We know that "Questioned" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case questioned = challenged.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CHALLENGED mean?
CHALLENGED verb- To invite (someone) to take part in a competition.
- To dare (someone).
- To dispute (something).
- To make a formal objection to a juror.
- To claim as due; to demand as a right.
- To censure; to blame.
- To question or demand the countersign from (one who attempts to pass the lines).
- To object to the reception of the vote of, e.g. on the ground that the person is not qualified as a voter.
- To take (a final exam) in order to get credit for a course without taking it.
- Lacking some physical or mental attribute or skill ; used after adverbs to make politically correct adjectives.
- Used following adverbs to make adjectives in imitation of and mocking adjectives of this kind.