A former colleague left our company after completing his NEBOSH and signing a contract stating if he left within 2 years he would have to pay an amount back he stated he does not have to pay for his NEBOSH course due to it being health and safety training and that it was a necessity for his job role at the time
is this correct or is he still liable to pay.

This is not an uncommon request by a company, if they invest in a member of staff they may get the employee to sign to state that they will pay all or part of the investment back if they leave within a certain time span.
I think this is more an HR issue but if you sign a contract you can be liable to pay.
The Company may or may not pursue it and could be well within their rights to do so.

I am not commenting from any legal expertise but from previous experience.
My understanding is that such contractual arrangements are common. They should , however, only cover formal training that enables an employee to gain a skill that will/could be useful elsewhere.
Any disputes as to unlawful deduction, should the clause need to be applied, would be tested against whether the costs/charges are seen as a genuine pre-estimate of the damages/loss that the employer has suffered. If this test is not met then it is considered a penalty on the employee and cannot be enforced. Many such contracts work on a sliding scale where the amount to be repaid reduces the closer to the two years the parting of ways occurs; the logic being that the employer has gained some benefit from the acquired skills/knowledge
Best to check with HR or legal as the matter, as usual, is not clear cut. The fact that it is OSH related training is unlikely to helpful to the employee in this case because the trainig does provide usable skills/knowledge. Hope this helps but please don’t take it as authoritative legal comment.

P48

The bottom line really is how much will it cost the company to try and in force it. Whenever I talk to our solicitor they put the clock on at 20 quid for a five minute chat the nebosh course won't take long to be wasted. How much do you think a day in the court will cost? I would ignore all communications unless I needed a reference !

Again be careful with the words here...H&S Training it isn't in my mind this is career enhancement or career Training. If him keeping the role was dependant on the qualification then if he failed then he would have been out of a Job....so whatever he signed he signed as a career enhacement not H&S Training.