UK Anti-Doping (UKAD) has confirmed it is investigating accusations of "wrongdoing" in cycling.
The news comes following allegations by ex-Team Sky rider Jonathan Tiernan-Locke made in an interview with BBC Sport that painkiller Tramadol was "freely offered" during the Road World Championships four years ago.
Meanwhile, reports in the Daily Mail suggested UKAD had launched an investigation into the alleged delivery of a medical package to Team Sky by a British Cycling coach in 2011.
A spokesperson for UKAD said: "We are investigating allegations of wrongdoing in cycling. In order to protect the integrity of the investigation, we will not comment further."
In a statement in response to the Daily Mail claims, Team Sky said an internal review had been conducted and that they were "confident there has been no wrongdoing".
Former Team Sky rider Bradley Wiggins, who won the 2012 Tour de France with the team, has come under scrutiny after a leak of his private medical data as part of the Russian cyber-hack on the World Anti-Doping Agency (WADA) revealed he was granted a Therapeutic Use Exemption (TUE) to use asthma medication salbutamol from 2008, while triamcinolone acetonide was approved in 2011, 2012 and 2013.
TUEs allow athletes to use banned substances if they have a genuine medical need and there is no suggestion that Wiggins, Team Sky or any other athlete named in the 'Fancy Bears' leaks has broken any rules.