The incident has brought both British Cycling and Team Sky into widespread media focus, and both organisations have been the subject of a UK Anti-Doping investigation and an inquiry into doping in UK sport run by the Digital, Culture, Media and Sport Select Committee in Parliament.
The investigation and inquiry are trying to ascertain what was in the package, and whether it was within the rules.
Here we present a concise summary of the people and organisations involved in the inquiries, and a timeline of events so far.
Who's who and what's what
British Cycling (BC) - national governing body for cycle sport in the UK. Run the national cycling teams, including the Olympic cycling squad.
Team Sky - British registered WorldTour-level professional cycling team, created in 2010. Bradley Wiggins rode for Team Sky from 2010 to April 2015.
UKAD - UK Anti-Doping, the 'national organisation dedicated to protecting a culture of clean sport'. UKAD are conducting an on-going investigation into British Cycling and Team Sky, which has not yet been given an end date.
Digital, Culture, Media and Sport (DCMS) select committee - a group of British MPs that are currently conducting an inquiry into doping in UK sport. No end date has been set.
Dave Brailsford - team principal of Team Sky.
Simon Cope - former British Cycling women's road and endurance academy coach.
Dr Richard Freeman - British Cycling medic, formerly Team Sky medic.
Nicole Sapstead - chief executive of UKAD.
Shane Sutton - former technical director of BC and Team Sky coach.
Bradley Wiggins - former Team Sky pro rider between 2010-2015. Won the 2011 Critérium du Dauphiné and reportedly received Fluimucil at the race.
Fluimucil - a decongestant medicine. Reportedly what was in the package taken from England to France. It is not on the World Anti-Doping Agency's list of banned substances. Fluimucil is available over-the-counter in France.
Timeline of events
June 8 2011: British Cycling employee Simon Cope picks up a jiffy bag from BC's headquarters in Manchester that has been left on his desk. It is addressed to Dr Richard Freeman, and Cope has been asked by Shane Sutton to deliver it to Team Sky and Freeman at the Critérium du Dauphiné race in France.
June 11 2011: Cope stops off in London to attend a race, and stays overnight before travelling to Gatwick to catch his flight to Geneva.
June 12 2011: Cope arrives at Geneva airport and then drives to the Dauphiné in La Toussuire, France. He delivers the package to Freeman, as instructed, and later flies back to Britain, giving Shane Sutton a lift to the airport. Wiggins wins the 2011 Critérium du Dauphiné. Wiggins is given decongestant medicine Fluimucil via a nebuliser after the race. Wiggins told UKAD during its 2016/17 investigation that he did not know whether the medicine came from the package or not.
June 28 2011: Wiggins given a Therapeutic Use Exemption (TUE) certificate for Triamcinolone acetonide ahead of the 2011 Tour de France. He withdrew from the 2011 Tour on July 8 after crashing and breaking his collarbone.
July 22 2012: Wiggins wins 2012 Tour de France.
Unspecified date 2014: Dr Richard Freeman told UKAD in March 2017 that his laptop containing medical records was stolen while he was on holiday in Greece during 2014.
September 8 2015: First oral evidence session of DCMS select committee inquiry into doping in UK sport, originally covering doping in athletics.
April 27 2016: Shane Sutton resigns from his post as technical director in BC after allegations of sexism and bullying.
June 14 2016: 'Whistleblower' Dan Stevens provides oral evidence to DCMS select committee regarding doping in UK cycling.
September 15 2016: A hacking group calling themselves Fancy Bears publish Therapeutic Use Exemption certificates for British cyclists Wiggins and Chris Froome. Fancy Bears obtained the TUEs after illegally accessing World Anti-Doping Agency (WADA) files held for Rio 2016 Olympic Games athletes. Wiggins' has three TUEs for Triamcinolone acetonide, administered via injection, on June 29 2011, June 26 2012 and April 22 2013, as well as for asthma medication.
September 25 2016: Wiggins appears on BBC's Andrew Marr show, and says he was not trying to gain an "unfair advantage" by using Triamcinolone acetonide.
October 6 2016: The Daily Mail publishes an article saying that UKAD are investigating allegations that a medical package was delivered to Wiggins at the 2011 Critérium du Dauphiné. At that point, the contents of the package are unknown. Separately, former GB and Team Sky rider Jonathan Tiernan-Locke tells the BBC that controversial painkiller Tramadol was 'offered freely' to riders during the 2012 World Championships.
December 19 2016: Dave Brailsford and Shane Sutton appear before DCMS select committee in Parliament. Brailsford reveals that he has been told by Freeman that the package contained Fluimucil for Wiggins. It's the first time that the public have been made aware of the package's contents.
January 24 2017: Former pro and Great Britain rider Nicole Cooke gives oral evidence to DCMS select committee. She says that cycling's anti-doping efforts are "the wrong people fighting the wrong war, in the wrong way, with the wrong tools".
February 9 2017: Jonathan Browning announced as new BC chairman, replacing Bob Howden.
March 1 2017: Evidence given to CMS select committee by Simon Cope and Nicole Sapstead. Cope says that he was unaware of the contents of the package he was asked to deliver. Sapstead gives information of UKAD's investigation into BC and Team Sky, saying that UKAD could not 'confirm or refute' that Fluimucil was in the package as no medical records were kept. Freeman was originally scheduled to appear at the hearing, but withdrew due to illness - it is likely that he will have to answer MPs' questions at a later date.
March 2 2017: BC admits that there are 'serious failings' in its keeping of medical records. Damian Collins MP, the chair of the CMS select committee, says that Wiggins will not be called as a witness.
March 7 2017: Team Sky publishes a letter from Brailsford to the DCMS select committee, and a document titled 'Team Sky - Points of clarification on UKAD investigation and evolution of anti-doping and medical practices'. The letter says that the investigation has "highlighted areas where mistakes were made by Team Sky", and also says "many of the subsequent assumptions and assertions about the way Team Sky operates have been inaccurate or extended to implications that are simply untrue".
March 28 2017: Dr Freeman issues a nine-page document addressing many of the questions posed to him by MPs from the select committee. However, Damian Collins MP said that the new evidence "leaves major questions outstanding for Team Sky and British Cycling".
March 5 2018: DCMS Select Committee publishes its report into 'Combatting Doping in Sport', which concludes that they cannot state what was in the package. It reads: "The Committee is not in a position to state what was in the package delivered to Team Sky by Simon Cope at La Toussuire on 12 June 2011. Dr Freeman has stated that it was Fluimucil, and an allegation was made to UKAD, and has been seen by the Committee, that says it was triamcinolone. We do not believe there is reliable evidence that it was Fluimucil as Dr Freeman will not now confirm it was and, previously, he was the only reported source of this information.
"The mystery surrounding the delivery of the package, and the extraordinary lengths to which Team Sky went to obtain an easily available drug delivered to them, have also fuelled speculation as to what the package might have contained. There remains no documented evidence as to what was in the package."
The report was highly critical of Sky's record-keeping, saying: "How can David Brailsford ensure that his team is performing to his requirements, if he does not know and cannot tell, what drugs the doctors are giving the riders?"
UKAD issues a statement in response to the report saying that the case relating to the package is closed with no anti-doping rule violations issued.
However, UKAD's Sapstead said that the case could be re-opened if fresh evidence or information surfaces.
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