"defamatory comments" is a correct and usable phrase in written English.
You can use it when referring to a statement that is damaging to another person's reputation or character. For example, "The company was sued for publishing defamatory comments about a rival."
Contrast these examples with defamatory comments in the United States.
I have begun legal proceedings against Hadley Freeman of the Guardian on her defamatory comments about me.
Later that day, Mr Galloway wrote on Twitter: "I have begun legal proceedings against Hadley Freeman of the Guardian on her defamatory comments about me.
The ice roads are a cheaper alternative to ferries and a number of people posted abusive and defamatory comments about the company's main shareholder on the site.
It would criminalise "group libel": "defamatory comments made in public and aimed against a [religious, ethnic, sexual etc.] group...with a view to inciting to violence, slandering the group, holding it to ridicule or subjecting it to false charges".
To tame the unruly power of the Web, the Supreme People's Court declared that "false defamatory" comments, viewed five thousand times or forwarded five hundred times, could result in a prison sentence of up to three years.
If someone accuses you of posting something improper, such as their copyrighted material or a defamatory comment about them, deal with it quickly.
The complaint objects to an allegedly defamatory comment that discussed Rescue One Financial, citing two blog posts, one of which is about Financial Rescue.
And, in the field of libel we were unanimous in the New York Times case in rejecting the argument that because defamatory comment had been printed as an advertisement for profit it was less deserving of protection.
prior to the delivery to GNM of the final draft of the Publication, Your lawyers shall have fully investigated every defamatory allegation in the Publication and shall have satisfied themselves that each and every such allegation is true and can be justified; and, that every defamatory comment contained in the Publication is based on true facts stated in the Publication.
If you publish a defamatory comment claiming that someone is a paedophile, without any knowledge of the underlying facts of the case (which would include social media users who named McAlpine), you are clearly displaying reckless disregard for the truth of that allegation.
