Timeline of events since hackers Fancy Bears leaked medical records of cyclists

UK Anti-Doping on Thursday night said it was examining an "allegation of wrongdoing within cycling". The investigation follows scrutiny of Team Sky and Sir Bradley Wiggins over the use of therapeutic use exemptions (TUEs) and allegations of the use of a legal but controversial painkiller. Here Press Association Sport plots a timeline of the events.

September 15

Tour de France winners Sir Bradley Wiggins and Chris Froome are among five British athletes whose medical records with the World Anti-Doping Agency are leaked by computer hackers. The details were made public by cyber espionage group 'Fancy Bears', believed to be from Russia.

September 17

Wiggins denies that controversial Belgian doctor Geert Leinders had any involvement in the decision to apply for permission to use a banned steroid to treat allergies before three major races. Wiggins used triamcinolone, the same drug Lance Armstrong tested positive for at the 1999 Tour de France. The five-time Olympic champion also clarified comments made in his 2012 autobiography that he strictly observed cycling's 'no needles' policy, despite already having injections of triamcinolone before the 2011 and 2012 editions of the Tour, with a third coming shortly before the 2013 Giro d'Italia.

September 23

One of Wiggins' former team doctors expresses surprise at the decision to allow him to use triamcinolone. Prentice Steffen, Wiggins' doctor at Garmin Slipstream, with whom he finished fourth in the 2009 Tour - later upgraded to third after Armstrong's disqualification - questioned the decision of the UCI to grant Wiggins a TUE. Steffen told the BBC's Newsnight: "It doesn't look right from a health or sporting perspective."

September 25

Wiggins denies he was trying to gain an "unfair advantage". In an interview with BBC1's Andrew Marr Show, Wiggins said: "(The triamcinolone) was prescribed for allergies and respiratory problems. This was to cure a medical condition. This wasn't about trying to find a way to gain an unfair advantage. This was about putting myself back on a level playing-field in order to compete at the highest level."

September 26

Team Sky principal Sir Dave Brailsford defends the decision to get the TUEs for Wiggins. Team Sky have a much-publicised "zero tolerance" attitude towards doping. And Brailsford reiterated his belief that the team had done nothing wrong and denied that this was remotely similar to the doping so prevalent in the sport a decade ago. Brailsford told the BBC: "What we're talking about here is Bradley having a need, the team doctor supporting that, an expert giving their opinion that this is the medicine that is required, and that then going to the authorities who say 'we agree with you, and here's the certificate that gives you the permission to use that medication'. I've got trust in (the TUE) process and the integrity of that process."

September 27

Froome, a three-time Tour winner, described the TUE rules as "open to abuse" and in need of urgent reform. In a post on his Twitter feed, Froome said he does not have a "win at all costs" approach to sport and has never pushed the boundaries of what is allowed. And in an apparent reference to the controversy surrounding his former Team Sky team-mate Wiggins, Froome said athletes need "to take responsibility for themselves, until more stringent protocols can be put in place".

September 30

Wiggins makes a further attempt to defend his reputation in an interview with the Guardian. He said he was "fully aware" of the history of triamcinolone, "the taboo surrounding it all ... the misuse and the abuse of this drug in the past" and of those who believe its use is unethical. But he stressed the medical need. He told the Guardian: "Without all the context of someone's history then I could see that on paper maybe, especially the way some of it has been reported. It was for a very specific thing ... to treat something that was historically a problem for me and could be quite a serious problem for me."

October 6

Jonathan Tiernan-Locke, who served a two-year anti-doping ban until early 2016, alleges he was offered a controversial and powerful painkiller while representing Great Britain at the 2012 Road Cycling World Championships. Tramadol has been on the World Anti-Doping Agency's monitoring list for a number of years, with concerns over its side effects. Tiernan-Locke told the BBC it "was offered freely around". Sources within British Cycling say the team doctor at the 2012 Road Cycling World Championships denies the claim.

October 7

UK Anti-Doping says it is examining an "allegation of wrongdoing within cycling". The announcement came as the Daily Mail reported UKAD is investigating Team Sky and Wiggins over the contents of a medical package. The newspaper alleges a package was delivered to Team Sky in France on June 12, 2011, and it reports that UKAD is looking at what that contained. UKAD did not go into any detail about the allegation it is looking at and mentioned no names, while Wiggins' representatives believe he is not a subject of the investigation.