An inquiry was launched in September 2016 after British newspaper the Daily Mail reported a mystery package had been delivered to Richard Freeman, the doctor of now retired Tour de France victor Bradley Wiggins, then a Sky rider. Video footage showed that he had indeed been at the vehicle.
Richard Freeman, the doctor at the centre of the controversy, insisted the parcel only contained the legal decongestant fluimucil.
An internet hack believed to have been carried out by the Russian Fancy Bears group revealed Wiggins had medical exemptions to use the banned drug triamcinoline at the 2011 Tour de France, and again at the 2012 Tour de France and 2013 Giro d'Italia.
It was in this context that UKAD investigated the jiffy bag delivery, seeking to determine exactly what was in the package.
UKAD state the investigation serves as a reminder to all those responsible for medical record-keeping within sport to ensure that medical record policies are fit for objective. 'It follows that UKAD does not intend to issue any anti-doping charges in relation to the package'.
'As with all investigations, UKAD may revisit matters if new and material information were to come to light.
Team Sky issued a brief statement welcoming the news. "This investigation has now been brought to a close", it said.
"We have always maintained that there was no wrongdoing and we have co-operated fully with UK Anti-Doping over the past year".
"Since our inception as a new pro cycling team in 2010 we have continually strengthened our systems and processes so they best support our strong commitment to anti-doping".
"UKAD's findings represent an organisation and culture that, despite delivering on the world stage, did not meet the high standards that British Cycling today holds itself to", said Julie Harrington, British Cycling chief executive.
In summarising the investigation, UKAD's statement concluded: "Put simply, due to the lack of contemporaneous evidence, UKAD has been unable to definitively confirm the contents of the package".
"As with all UKAD investigations, our work has been thorough and extensive, and I can reassure the public that we treat every credible allegation with the utmost seriousness".
"What's clear from UKAD's statement is if Sky and British Cycling had kept proper medical records, this could have been wrapped up a lot sooner". 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.
Dr. Freeman resigned from his British Cycling post last month, having been unavailable for further interview as a result of ill-health.
"We have written to British Cycling and a copy of this letter has also been sent to UK Sport and Sport England".
"Finally, we have referred some information to the GMC, and will cooperate with the GMC as necessary in respect of that information".
British Cycling has responded with its own statement, admitting that it had fell short.
However, Ukad said that it would hand information to the General Medical Council, which could result in it taking on the investigation.
'British Cycling have implemented a number of significant changes to the management of our medical services to the Great Britain Cycling Team following a review instigated in March by chair Jonathan Browning, shortly after his appointment, ' she continued.
It was couriered personally by Simon Cope, the coach to British Cycling's women's team, from British Cycling's headquarters in Manchester to the finish of the Criterium du Dauphine in Chatel.
The relationship between BC and Team Sky were also investigated, with staff and resources often shared between the two entities. This led to some failings in the way that processes and people were managed.
She said nobody is now simultaneously employed by both organisations and they have their own practices for managing medical records.