Starts to interrupt reporter, asking questions in a form of Arabic (5)
I believe the answer is:
iraqi
'a form of arabic' is the definition.
(Iraq is in Arabia)
'starts to interrupt reporter asking questions in' is the wordplay.
'starts to' suggests taking the first letters.
The initial letters of 'interrupt reporter asking questions in' is 'IRAQI'.
(Other definitions for iraqi that I've seen before include "Asian" , "Nationality of citizen of Baghdad" , "around Baghdad?" , "Language" , "Native of Fallujah, perhaps" .)