Tony Gunawan: Two Olympics, two countries, two golds?

At the 2000 Sydney Olympics, Tony Gunawan won gold in doubles badminton for his home country of Indonesia.

He moved to California to start a new life with his family and began coaching and competing for the US - winning the country's first ever World Cup gold medal for a men's double team.

Gunawan was unable to compete for the US at the Olympics in Athens and Beijing, however, because he was not an American citizen.

Having gained citizenship last summer, Gunawan qualified for London Games. His doubles partner, Howard Bach, is also an adopted American athlete. Bach was born in Vietnam and moved to the US at the age of three.

Produced by the BBC's Franz Strasser.