Claims guard’s involved in more than one scam (8)
I believe the answer is:
contends
'claims' is the definition.
('contend' can be a synonym of 'claim')
'guard's involved in more than one scam' is the wordplay.
'guard' becomes 'tend'.
'involved in' means one lot of letters goes inside another.
'more than one scam' becomes 'cons'.
'tend' going inside 'cons' is 'CONTENDS'.
(Other definitions for contends that I've seen before include "Fights or argues" , "Strives; maintains" , "Vies" , "Strives against another" , "Maintains or asserts" .)