First of all, in 2009 the IPC website www.paralympic.org published the qualification criteria for the IPC Athletics World Championships in Christchurch.
This criteria set out clearly what the eligible class would be for each medal event.
This stated that the classes for the marathon were T11, T12, T46 and T54 - not T42 which is Richard Whitehead's class.
This meant that as early as 2009 it was clear there would be no marathon event for Richard to participate in.
The IPC cannot bar an athlete and neither can a federation or National Olympic Committee try to enter an individual into a medal event that simply does not exist.
The reason why the IPC has not organised a T42 marathon in Christchurch is that there are very few marathon runners around the world in the T42 class.
We do sympathise with Richard on this issue as he is the world record holder for both the T42 full and half-marathons and would be a strong contender for gold in any championships.
However, for the credibility of the sport it is not logical to organise a marathon medal event when there are so few T42 runners – in Christchurch it was likely that we would have had less than three runners in the event had it been organised.
What sometimes happens in Paralympic sport when there are limited numbers of athletes in certain classes, is that athletes are allowed to 'move-up' a class. This however, only makes sense when the methods of impairment are similar or affect similar regions of the body.
For example the visually-impaired classes of T11, T12, T13 are sometimes combined as the method of impairment is similar and affects the same area of the body.
In Christchurch Richard was hoping to "move-up" a number of classes from T42 to T46 and compete in the marathon.
Richard is classed as a T42 athlete because he has a double-leg amputation above the knee. T46 class athletes have a single above or below elbow amputation or impairment.
Therefore there is no single argument to consider a leg amputee (T42) to compete 'up' a class with arm amputees (T46) as the impairments are dissimilar and affect totally different parts of the body.
The only thing similar about the classes is the letter T and the fact the numbers are in the forties!
We are aware of the case presented to us by Richard's lawyers. This is ongoing and we hope it will be resolved soon.
In the meantime we wish Richard and the 1,000 other athletes luck in their quest for medals at the IPC Athletics World Championships in Christchurch.
Craig Spence is media and communications senior manager at the International Paralympic Committee