LEWISTON, Maine (AP) Actor Patrick Dempsey says someone is impersonating him online to ask his fans to give money to either him or his Maine-based nonprofit.

Dempsey tweeted Monday that “people have been impersonating me and asking my fans for money (through social media).” Nancy Audet, spokeswoman for the Dempsey Centers in Lewiston and Portland, tells the Sun Journal that Dempsey is not asking anyone for money.

Audet says the scam has been going on for a while, saying people set up fake accounts and sending messages pretending they are seeking money for the Dempsey Centers or the actor himself.

Dempsey was born in Maine and is best known for his role as Dr. Derek “McDreamy” Shepherd in “Grey’s Anatomy.” His Maine nonprofit seeks to help those affected by cancer.