When is an international athlete not all they seem? When they swap nationalities to where the grass is greenest. Sports reporter Claire Hughes looks at five sports, where people have cut their patriotic cloth accordingly.

Greg Rusedski, with his homegrown all-American square jaw, lovely teeth and purring accent was actually strutting his stuff for Great Britain in this week's Davis Cup misery for all the good it did.

The Canadian-born left-hander raised eyebrows when he applied for British citizenship back in 1995. His mum was born in Dewsbury before moving to Canada as a child, and it was the burgeoning love affair with Lucy Connor - now his wife - that had him hooked.

The enormously patriotic Canadians were left wounded by the 'betrayal' and sceptical Brits would continually refer to his trans-Atlantic roots whenever he lost.

Now, 11 years on and he is finally getting the acknowledgement from the majority of tennis fans who have fallen in love with his emotional honesty both on and off court. At least he is still battling for Britain in the Davis Cup, unlike his 'true' British comrade Tim Henman.

There's something about his slightly wild enthusiasm that marks Kevin Pietersen out as not your average English cricketer.

Probably because he's not. Born in Pietermaritzburg, Natal, South Africa, Pieterson apparently never doubted that he would pull on his pads for England - a role model for young male self-esteem if ever there was one.

He turned his back on his home country because he didn't agree with the quota system in practice down there, and then traded in his mum's passport for a shot at the big-time from inside the England camp.

Two years after qualifying for selection, he is the proud owner of an MBE having stroked his fair share of runs in the Ashes Test that beat the Aussies.

Sheffield-born swimmer Zoe Baker shrugged off her British allegiance in 2001 to swim for New Zealand.

She had been living in Christchurch since 1999 after falling in love with the country at a training camp in 1996 leaving her to clock up the air miles to fulfil her Great Britain commitments.

It was a hard slog but it seemed to be paying off when the 29-year-old sprinter was crowned a Commonwealth gold-medal winner at the Manchester Games in 2002 under the red rose of England.

But the controversial arrival of Australian coach Bill Sweetenham left her clamouring to turn her citizenship into a full-blown black-capped silver fern costume.

Despite leaving him behind, Baker still had her Melbourne 2006 chances upset by the Aussies after they ranked a 1-2-3 in the 50 metres breaststroke final, leaving Baker fourth.

Closer to home, Robin Francis, who grew up in York after moving here from South Africa in his childhood, has also switched to his South African roots.

If you're looking at a sport where passport-swapping is as hotly pursued as the latest imported Japanese card-trading game, it has to be athletics.

Irish long distance runner Sonia O'Sullivan was in the news in the run-up to the Commonwealth Games as she kept her fingers crossed for clearance to complete her Down Under switch to wear a different shade of green with the gold of Australia.

US sprinter Malachi Davis was quick on the mark when he discovered he could have a shot at international competition if only he was British.

Strict selection rules in the States meant that Davis would never quite make the squad. But the determination that saw him go from being a leukaemia-stricken eight-year-old to a sprinter with world-class potential, found him an opportunity through his London-born mum.

The psychology graduate had never been outside his country of birth until six days before he received his British passport - and that a hop to Canada.

And so to football, with one glaring omission - or is it? Ryan Giggs has had people scratching their heads for years over his decision to 'choose' his native Wales over England, whom he captained at schoolboy level.

The reality is with both parents and sets of grandparents Welsh, he had no choice in the matter.