Dame Katherine Grainger tells Dan Roan she knew 'very few people who had TUEs' when she was rowing

UK Sport chair Dame Katherine Grainger is "surprised and disappointed" after former Team Sky and British Cycling coach Shane Sutton said riders legally used banned drugs to "find the gains".

Sutton told a BBC Two documentary on Sunday that he and his riders "never crossed the line" in their use of therapeutic use exemptions (TUEs).

Grainger, an Olympic gold medal-winning rower, said: "I don't know any athlete who would want to go near TUEs for any reason other than if it was necessary from a medical point of view.

In Cycling's Superheroes; The Price of Success, Sutton was asked in which circumstances he would have applied for a TUE to get permission for a rider to use a prohibited drug on medical grounds.

"If you've got an athlete that's 95% ready, and that little 5% injury or niggle that's troubling, if you can get that TUE to get them to 100%, yeah of course you would in those days," he said.

"The business you're in is to give you the edge on your opponent… and 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've never done."

Sutton was also asked whether "finding the gains might mean getting a TUE".

He replied: "Finding the gains might be getting a TUE? Yes, because the rules allow you to do that."

Grainger, a five-time Olympian who won gold at London 2012, said those comments were "disappointing".

"When I was an athlete, I knew very few people that got TUEs and, as far as I was aware, it was very hard to get it," she said.

"There are very strong reasons why a TUE might be needed from a purely medical point of view and that's why they exist. Anything short of that goes in to grey areas and brings in risks to reputation."

Asked if using TUEs for athletes at 5% below their best was acceptable, she said: "It's definitely not in the spirit of it. They came in for a clear medical purpose."

Sutton's comments came amid continued controversy over the three TUEs granted to Briton Sir Bradley Wiggins before major races in 2011, 2012 and 2013.

Wiggins' use of the corticosteroid triamcinolone to treat asthma and allergies was revealed when hackers released medical files stolen from the World Anti-Doping Agency (Wada) last year.

The 2012 Tour de France winner's TUEs were approved by the authorities and cycling's world governing body the UCI, and there is no suggestion he or Team Sky broke any rules. Both have strenuously denied any wrongdoing.