A man claiming to be a whistleblower has been jailed for five years for making online postings alleging a garda was corrupt and unfaithful to his wife.

An architect who allegedly harassed a sergeant by posting messages about him online considers himself a “whistleblower” who is exposing Garda corruption, a trial has heard.

A Dublin man has gone on trial accused of harassing a garda sergeant by phoning him and posting online messages calling him “lying” and “corrupt”.