Microsoft has launched an investigation into allegations of fraud on Xbox Live, according to CNET (via Next Generation).

Various reports have surfaced in recent weeks of Xbox Live accounts being hijacked and Gamertag IDs being stolen, and some users are resorting to collecting their own examples of fraudulent activity.

It's not known whether Xbox Live's security has been breached or there is a more mundane explanation for the mystery.

RRecently, there have been reports of fraudulent activity and account theft taking place on the Xbox Live network. Security is a top priority for Xbox Live, and we are actively investigating all reports of fraudulent behavior and theft," a Microsoft spokesman told CNET.