Zac Efron has fuelled speculation that he is making a return to the High School Musical franchise after posing outside a tell-tale location from the series.The Hollywood actor, 34, rose to fame in 2006 when he first starred as the character Troy Bolton in the blockbuster film franchise. He later reprised the role in 2007 in the first sequel of the film, and then again in the third instalment in 2008 – the first to be on the big screen.