LONDON (AFP) – Former Great Britain and Team Sky coach Shane Sutton has admitted to using therapeutic use exemptions (TUEs) to give the cyclists he worked with an edge.

Former Sky cyclist Bradley Wiggins had previously said the TUEs he received at the 2011 and 2012 Tours de France and the 2013 Giro d'Italia were to treat pollen allergies.

This week, U.K. Anti-Doping (UKAD) ended an investigation into alleged wrongdoing by British Cycling and Team Sky, which share a Manchester headquarters, without bringing any charges.

"If you've got an athlete that's 95 percent ready and that little five percent injury or niggle that's troubling them, if you can get that TUE to get them to 100 percent, then of course you would in those days," Sutton said in a BBC television documentary due to be broadcast on Sunday.

"The business you are in is to give you the edge on your opponent. Ultimately, at the end of the day, it's about killing them off. But definitely don't cross the line and that's something we have never done."

TUEs permit athletes to use drugs that would otherwise be illegal.

A key tenet of the Team Sky philosophy is the concept of "marginal gains," which refers to minute improvements that, collectively, can improve performance.

Asked if the use of TUEs was part of that approach, Sutton tells the documentary: "Finding the gains might mean getting a TUE? Yes, because the rules allow you to do that."

Wiggins, who retired last year, has described UKAD's investigation into the contents of a jiffy bag delivered to Sky during the 2011 Criterium du Dauphine as a "malicious witch hunt."

His TUEs were granted for use of the banned corticosteroid triamcinolone.

Sky principal Dave Brailsford tells the documentary the TUEs granted to Wiggins, who became France's first Tour de France champion in 2012, were medically necessary.

Sutton is now the head coach of China's track cycling team, having left British Cycling in April 2016 after allegations of discrimination and bullying.