Gardaí are investigating a series of "threatening or intimidating" messages sent to at least one General Election candidate in the Cork East constituency.
Social Democrats candidate Ken Curtin says "nasty and false" allegations have been made against his family, and he has formally complained to Gardaí.
It follows a separate bullying row within Sinn Féin in the constituency, which led to TD Sandra McLellan deciding not to contest her seat.
Social Democrats candidate Ken Curtin says threats, theft and defacement of posters is "undemocratic".
He said: "There does seem to be an element of skulduggery going on. The nicest way I could word it is ungentlemanly conduct.
"But there is literally a nasty element that there is no place for in an election. I don’t think it's doing any candidate any favours."