Expert on Muslim leader brought into court (10)
I believe the answer is:
consultant
'expert' is the definition.
(consultant is a kind of expert)
'on muslim leader brought into court' is the wordplay.
'muslim leader' becomes 'sultan' (I am not sure about this - if you are sure you should believe this answer much more).
'brought into' means one lot of letters goes inside another.
'court' becomes 'ct' (abbreviation used in road names).
'on'+'sultan'='onsultan'
'onsultan' put inside 'ct' is 'CONSULTANT'.
Can you help me to learn more?
(Other definitions for consultant that I've seen before include "Adviser" , "See 1 across" , "Specialist" , "Senior hospital doctor" .)