UK Anti-Doping has announced that there will be no charges as a result of its 14-month investigation into allegations of wrongdoing at British Cycling and Team Sky.
UKAD started the investigation in September 2016 after a mystery package was delivered to Sir Bradley Wiggins following the conclusion of the 2011 Criterium du Dauphine race in France.
It was alleged that the bag contained a banned substance, but British Cycling told a parliamentary select committee earlier this year that it was fluimucil -- a legal decongestant.
The anti-doping agency has now ended its inquiry after it was unable to find sufficient evidence to determine what was in the package delivered to the British Cycling doctor, Dr Richard Freeman.
A statement on the UKAD website read: "Put simply, due to the lack of contemporaneous evidence, UKAD has been unable to definitively confirm the contents of the package.
"The significant likelihood is that it is now impossible to do so."
As part of their investigation, UKAD interviewed 37 members of Team Sky and British Cycling, including medical professionals and riders from both organisations.
"I can confirm that UKAD does not intend to issue any anti-doping charges as a result of the investigation into the package," UKAD Chief Executive Nicole Sapstead added.
"Our investigation was hampered by a lack of accurate medical records being available at British Cycling," she added.
"This is a serious concern. As part of their conditions to receive public funding from UK Sport and other Home Country Sports Councils, all sports governing bodies must comply with the UK National Anti-Doping Policy. In this case the matter was further complicated by the cross over between personnel at British Cycling and Team Sky."
British Cycling chief executive officer Julie Harrington said: "I would like to thank Nicole Sapstead and her team at UKAD for the diligence and determination they have shown in investigating this matter.
"Their work on this, and throughout sport, is essential if we are to earn and retain the trust of athletes and fans.
"Today, based on our learning together there are clear boundaries and distinctions between our two organisations: no one is simultaneously employed by British Cycling and Team Sky; and we each have our own practices in place for managing athlete record," she continued.
"My focus now is on ensuring that we can give athletes and the public the reassurance they need to believe in our ability to win clean on the biggest global stages because of the systems and controls we have put in place. We are intent on ensuring that the integrity of our record keeping is never called into question again."