Home Office branch given hard sort of investigation? (2-5)
I believe the answer is:
in-depth
'sort of investigation?' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'home office branch given hard' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'office branch' becomes 'dept' (department, part of an office or workplace).
'given' means one lot of letters go next to another.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'in'+'dept'+'h'='IN-DEPTH'
Can you help me to learn more?
(Other definitions for in-depth that I've seen before include "With thorough and extensive investigation" , "searching" , "Comprehensive and thorough" , "Thorough and intensive" , "Detailed (investigation)" .)