 He was also the only non-African referee at the 2006 African Cup of Nations.In the 2010 World Cup in South Africa, Shamsul was appointed as a technical instructor by FIFA.In 2006, Shamsul was selected by FIFA as one of the official referees for the 2006 FIFA World Cup in Germany, only the second time a Singaporean had taken part in a FIFA World Cup after George Suppiah in 1974, also held in Germany (then West Germany).