Statement found in rubbish by Detective King (6)
I believe the answer is:
diktat
'statement' is the definition.
(I have seen 'Dogmatic statement ' mean 'diktat' so perhaps 'statement' could also mean 'diktat')
'rubbish by detective king' is the wordplay.
'rubbish' becomes 'tat' (low-quality items or material).
'by' is a charade indicator (letters next to each other).
'detective' becomes 'di' (Detective Inspector abbreviation).
'king' becomes 'K' (chess abbreviation).
'di'+'k'='dik'
'tat' after 'dik' is 'DIKTAT'.
'found in' is the link.
(Other definitions for diktat that I've seen before include "Categorical statement" , "Undemocratic decree" , "Harsh order or decree" , "arbitrary order" , "Harsh order given by someone with authority" .)