Article found under church altar unfortunately is phoney (9)
I believe the answer is:
charlatan
'is phoney' is the definition.
(I've seen this before)
'article found under church altar unfortunately' is the wordplay.
'article' becomes 'an' (indefinite article).
'found under' says to put letters next to each other.
'church' becomes 'ch' (common abbreviation).
'unfortunately' indicates an anagram (a bad or unfortunate spelling).
'altar' with letters rearranged gives 'arlat'.
'ch'+'arlat'='charlat'
'an' after 'charlat' is 'CHARLATAN'.
(Other definitions for charlatan that I've seen before include "One who falsely claims to be an expert" , "Impostor, deceiver" , "imposter" , "Person who falsely claims to be an expert" , "Quack, fraud, a flamboyant deceiver" .)