defamatory
adjective /dɪˈfæmətri/
  /dɪˈfæmətɔːri/
 (formal)- (of speech or writing) intended to harm somebody by saying or writing bad or false things about them
- The article was highly defamatory.
 
Oxford Collocations DictionaryDefamatory is used with these nouns:- allegation
 - remark