London 2012: The finest of fine margins

It was the first time an Olympic triathlon was decided with a photo finish, but the result is still disputed six days later. Sweden has asked the Court of Arbitration for Sport to award a gold medal to Lisa Norden as well as Switzerland's official winner Nicola Spirig who clocked identical times of one hour 59 minutes 48 seconds.

Spirig hit the tape with her stomach a fraction of a second before Norden, but the Swedes are convinced that their runner's torso hit the finishing line at the same time or even slightly before the Swiss.

Under International Triathlon Union rules, the winner is the competitor whose torso crosses the line first. Spirig appears to be leaning back as she reached the line.

The Swedish Olympic Committee and Swedish Triathlon Federation want both athletes to be ranked as joint winners. "The Swedish NOC and the STF consider that the ITU did not comply with its own rules because it may not have taken into account the position of the athletes' torsos when establishing the medal positions," said the court.

Photo finishes are aided by high-speed cameras – some can record 10,000 frames per second – and on the athletics track infrared sensors also help judges. Earlier this week, the technology was used in the men's 100m sprint to determine who should be awarded bronze. Blake Gatlin edged it by a 100th of a second over Tyson Gay. It was used to determine the fourth and fifth places in the women's 100m hurdles.

It was similarly used to determine the fourth and fifth places in the women's 100m hurdles, with the 'whited-out' photograph making it easier to see who reached the line first.

In the velodrome, a radio transponder on the bikes emits a code to antenna placed at the finish line. Photos are also used and showed that Victoria Pendleton beat Anna Meares in a heat by a centimetre, though the result was later quashed.