A simpleton, detective searched through the mullock (7)

I believe the answer is:

noodled

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'searched through the mullock' is the definition.
I can't judge whether this definition defines the answer.

'a simpleton detective' is the wordplay.
'a simpleton' becomes 'noodle' (I've seen this before).
'detective' becomes 'd' (this could be a standard abbreviation of which I'm unaware).
'noodle'+'d'='NOODLED'

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I've seen this clue in the Sydney Morning Herald.

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