SAS holding down French collaborator? (8)

I believe the answer is:

saunders

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'french collaborator?' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'sas holding down' is the wordplay.
'holding' means one lot of letters goes inside another.
'down' becomes 'under' (under means further down).
'sas' enclosing 'under' is 'SAUNDERS'.

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I've seen this clue in The Times.

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