Eminem track leaked

A new track featuring Eminem, apparently produced by Dr Dre, has been leaked onto the internet. According to reports, 'Number One' was included in a mix tape by DJs Big Mike and Neptune called '4th Quarter Pressure, Part 2'. It's rumoured that the track is to be included on Dre's next album 'Detox', not Eminem's comeback 'Relapse'. It was on YouTube, but it's no longer available "due to a copyright claim by a third party".