Megalomaniac releases income from Iberian port (6)
I believe the answer is:
malaga
'iberian port' is the definition.
I cannot understand how the remainder of the clue works.
(Other definitions for malaga that I've seen before include "Spanish port and resort town" , "City of Andalusia" , "where Spanish sailor lands?" , "Andalusian port; wine" , "Army rank; not shared" .)