Frenchman in Spanish city, expert swimmer (5,3)

I believe the answer is:

lemon dab

'swimmer' is the definition.
(I've seen this before)

'frenchman in spanish city expert' is the wordplay.
'frenchman' becomes 'm' (abbreviation for Monsieur - like 'Mr').
'in' is an insertion indicator.
'spanish city' becomes 'leon' (I've seen this in other clues).
'expert' becomes 'dab' (as in a dab hand).
'm' placed within 'leon' is 'lemon'.
'lemon'+'dab'='LEMON DAB'

(Another definition for lemon dab that I've seen is " Fish".)

I've seen this clue in The Telegraph.

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