Singer John Mayer has written a scathing message to an ex-girlfriend on his Internet site, prompting speculation he is referring to former lover Jessica Simpson.

The note refers to an ex who refused to accept their relationship had come to an end and Mayer warns the unnamed woman to "stop contacting" him.

Although Mayer urges his fans not to "read too far" into his message, Internet gossip sites insist the message is aimed at Simpson, who Mayer dated for nine months before they split in May 2007.

Mayer writes, "Dear Ex Lover, Perhaps you didn't understand the last time I told you to stop contacting me, so I'll do my best to spell it out for you. I do not wish to have you in my life anymore.

"I don't know how much more clear I can be about it. It would serve you best to move on with your life and find someone who can put up with you, because I'm done trying. I hope this is enough closure for you."

The 30-year-old's other high-profile romances include Jennifer Love Hewitt, who he dated in 2002. He was also briefly linked to actress Minka Kelly after his split from Simpson.