OTTAWA - The campaign team of the federal Liberal candidate in Nepean-Carleton has asked Ottawa police to investigate after his campaign signs were vandalized.

More than 100 signs placed on public property by Ryan Keon's campaign team were tagged with crude drawings resembling crosshairs of a rifle scope and other vandalism overnight on Friday.

Keon says there was black spray paint over the head shot as well as graphic and explicit messages left behind on the signs.

Keon is running against Tory Pierre Poilievre in the riding.

On Sunday, Prime Minister Stephen Harper denounced the graffiti.

He suggested there was no way his people were involved in the vandalism.

"Defacing other candidates' signs is not acceptable for any campaign," Harper said.

"Our campaign does not have the time to do that; we have enough to do to get our own signs up."