Eminem has been no stranger to controversy over the years, but his latest endeavour has left him with some explaining to do.

A track by the Detroit rapper, which was originally recorded in 2009, has surfaced and it mentions the Chris Brown and Rihanna assault case.

As you may recall, r'n'b star Brown - who has bafflingly somehow managed to salvage his career - was convicted of felony assault of his then-girlfriend in 2009, receiving 5 years of probation and 6 months' community service.

The Eminem track sees him rap: "I’m not playing, Rihanna, where’d you get the V.D. at?” and later, he says:: "Let me add my two cents / Of course I side with Chris Brown / I’d beat a bitch down, too if she gave my dick an itch now."

XXL report that the track was recorded during sessions for his  2009 album 'Relapse' and was a 'reference' track for the song that eventually became 'Things Get Worse'.

A spokesman for the rapper told the site: "This is a leak of something that’s over 10 years old. After Eminem recorded it, he scrapped it, and rewrote it. Obviously he and Rihanna have a great relationship.”

The pair have collaborated several times over the years, including 'Love the Way You Lie' (in 2010) and 'The Monster' (2013).

Neither Eminem not Rihanna have commented on the matter.