According to the Wikipedia page set up in his name, Warnecke is of Indo-Guyanese and German descent and was born in London.

Warnecke appeared on Newsnight in 1996 in the wake of the controversary that erupted when a white actor - Jeremy Irons - had been approached to play the part of the first President of Pakistan, Mohammed Ali Jinnah (http://www.independent.co.uk/arts-entertainment/from-othello-to-the-mins...). Asked by Jeremy Paxman, the presenter of Newsnight if he would consider whiting up to play Hamlet, Warnecke stated,

"Possibly yes. It depends on what form the production takes." He went on to observe: "We have a lot of second, third generation black, asian, Chinese and those actors are not being seen for parts which can easily be played by them. It's always from a white perspective."

~ Newsnight, BBC Two, 12 August 1996