Prohibit a clone being developed in this city (9)
I believe the answer is:
barcelona
'this city' is the definition.
(Barcelona is an example)
'prohibit a clone being developed' is the wordplay.
'prohibit' becomes 'bar' (to bar is to ban or prohibit).
'being developed' indicates an anagram.
'a'+'clone'='aclone'
'aclone' with letters rearranged gives 'celona'.
'bar'+'celona'='BARCELONA'
'in' acts as a link.
(Other definitions for barcelona that I've seen before include "Largest Spanish port" , "Chief port of Spain" , "Big city" , "Span. City" , "coastal city" .)