British hurdler Dai Greene believes that Rhys Williams and Gareth Warburton were "let down" after they were handed suspensions for failing drugs tests.

Williams missed four months of competition, while Warburton was issued with a six-month ban after illegal substances were found in their systems.

Both athletes claimed that they were not aware that their supplements contained a banned substance.

"In their situation I think they were very hard done by," BBC Sport quotes Greene as saying. "Sadly these two have been let down, but hopefully the next generation will learn from that.

"Maybe you could say that perhaps they didn't check everything, but no athlete checks everything. They trust what they are told by the supplement companies. They weren't at fault."

The UK National Anti-Doping Panel found the pair not guilty of intentionally cheating.