Deny fact so scandalous, showing no emotion (5-5)

I believe the answer is:

stony-faced

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'scandalous showing no emotion' is the definition.
I can't tell whether this defines the answer.

'deny fact so' is the wordplay.
'deny fact so' can be anagrammed to 'STONY-FACED'.
Though, I am not sure how this is indicated.

Can you help me to learn more?

I've seen this clue in The Irish Times.

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