A sign condemning violence against women and children erected on Phillip Island after the death of local mother Samantha Fraser has been vandalised.

The roadside billboard, erected by Westernport Water as part of a local campaign to fight family violence, has been defaced four times since it was put up more than a month ago.

A white ribbon sign on Phillip Island has been vandalised. Credit:Cecilia Rogers

The sign originally read: "It had to end. We must end violence against women and children."

But the sign has been vandalised four times since it was put up in late July, with the most recent incident prompting Westernport Water to make a police complaint. In one of the incidents, the vandals added the words "and men" to the end of the sign.