Arrest of chap from Prague announced (5)
I believe the answer is:
check
'arrest' is the definition.
('check' can be a synonym of 'arrest')
'chap from prague announced' is the wordplay.
'chap from prague' becomes 'czech'.
'announced' shows a homophone (sound like).
'czech' sounds like 'CHECK'.
'of' acts as a link.
(Other definitions for check that I've seen before include "Examine to determine accuracy" , "threat to king" , "retard!" , "Refrain or verify" , "Verify - rein in" .)