Told off old master producing false accusation (5)
I believe the answer is:
smear
'false accusation' is the definition.
(I've seen this before)
'told off old master producing' is the wordplay.
'off' suggests deleting specific letters.
'producing' is an anagram indicator.
'old'+'master'='oldmaster'
'oldmaster' with 'told' removed is 'maser'.
'maser' is an anagram of 'SMEAR'.
(Other definitions for smear that I've seen before include "Blur, smudge" , "Spread dirty substance, try to damage reputation" , "sample on slide" , "Discredit" , "Spread a greasy or sticky substance over something" .)