AceShowbiz -

Sienna Miller is back on the market. The much publicized actress is single again after her boyfriend Jamie Burke dumped her following her partying with P. Diddy after the Concert for Diana earlier this month.

Burke, a musician who has been dating Miller for eight months, was said to feel furious after learning the beauty had partied with the rap mogul. Besides, it seems that their long-distance relationship had taken its toll.

"He is based in New York, she has been in London", a friend of Burke revealed. "It is difficult to communicate on the phone. They couldn't make it work, so they split. But they are being mature about it and leaving things open."

Miller and Diddy first sparked romance rumors in January when they were seen partying in New York, before heading back to her hotel. Though either parties have denied there's chemistry between them, the fact that Diddy has just split with longtime girlfriend Kim Porter makes it possible for him and Miller to become lovers.