Questionable attitude NUS bans, wanting a fact check? (15)

I believe the answer is:

unsubstantiated

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'wanting a fact check?' is the definition.
I can't tell whether this defines the answer.

'questionable attitude nus bans' is the wordplay.
'questionable' indicates anagramming the letters.
'attitude'+'nus'+'bans'='attitudenusbans'
'attitudenusbans' is an anagram of 'UNSUBSTANTIATED'.

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I've seen this clue in The Telegraph.

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