European report on wrongdoing officially arrives (6,2)
I believe the answer is:
checks in
'arrives' is the definition.
Although both the answer and definition are verbs in their -s form, I can't see how they can define each other.
'european report on wrongdoing officially' is the wordplay.
'european' becomes 'czech' (Czech is an example).
'report' indicates a 'sounds like' (homophone) clue.
'on' is a charade indicator (letters next to each other).
'wrongdoing officially' becomes 'sin' (I can't justify this - if you can you should give a lot more credence to this answer).
'czech' is a homophone of 'check'.
'check'+'sin'='CHECKS IN'
Can you help me to learn more?
(Another definition for checks in that I've seen is " Chickens (anag)".)