Policemen admit evidence of debt – indeed, ample! (7)
I believe the answer is:
copious
'indeed ample' is the definition.
'copious' can be an answer for 'ample' ('copious' can be a synonym of 'ample'). I'm not sure about the 'indeed' bit.
'policemen admit evidence of debt' is the wordplay.
'policemen' becomes 'cops' (cop is a kind of policeman).
'admit' indicates putting letters inside.
'evidence of debt' becomes 'iou' (an IOU, 'I owe you').
'cops' placed around 'iou' is 'COPIOUS'.
Can you help me to learn more?
(Other definitions for copious that I've seen before include "Plentiful, existing in large amounts" , "Many" , "Providing loads of" , "full" , "abundance" .)