Less than a month ago, on the 20th of April, Stavros Niarchos had one hell of a birthday party specially arranged by the Hilton socialite. Then everything seemed just fine. But just yesterday, Elliot Mintz, Paris Hilton's representative, told People magazine, "It is not my policy to comment on my client's private life. But I would not offer a denial."

So it's over. No further details are clear but the Greek boy might have found out he's been dating a� let's just say someone who's been with lots of other people and whose anatomy is well known by tabloid readers and net surfers.

Or maybe the blond decided she's spent enough time with the Greek and just dumped him. Yet this is rather strange as the 25-year-old socialite and shipping heir Niarchos, 21, have been inseparable since getting together in 2005.

The party Paris threw for Stavros was a huge gathering of stars at the Hilton Hollywood residence, party people including Nicky Hilton, filmmaker Brett Ratner and Milla Jovovich, while Courtney Love and pal Billy Corgan made a surprise midnight appearance.