Paris Hilton Benji Madden Break Up Confirmed: Prince William Responsible?

and rocker boyfriendhave called it quits but "remain very good friends," according to Hilton's publicist Alanna McCarthy.

Rumors that there was trouble in paradise began a few weeks ago, then earlier this week photos of Hilton getting cozy with ex-boyfriend Stavros Niachros hit the net, leading to speculation that the relationship had taken a nosedive.

Now there are rumors that Prince William may be behind the split.

According to an inside source, the handsome prince and the hotel heiress spent time together while she was filming her reality show "Paris Hilton's British Best Friend" in London, and have plans to meet up in Australia to ring in the New Year.

Hilton and Madden are booked to attend a launch party for a new social networking site, Bongo Virus, on New Years Eve. Paris will host the event, while Benji is scheduled to spin.

Bongo Virus confirmed that Prince William is invited to the bash, but wouldn't comment further.

Prince William will not be confirming his attendance until just before the event "for security reasons," but he is "pretty keen to meet up with Paris," said the insider.

Whether Prince William has anything to do with the split or not, it doesn't seem that Paris is having any trouble moving on. In addition to being spotted with her ex in Miami on Saturday, she was also seen at West Hollywood hot spot Apple, partying with gal pals and dancing on the couches into the wee hours of Wednesday morning.