UK Anti-Doping (UKAD) says it is waiting for an explanation as to why cyclist Lizzie Armitstead was afforded a reprieve to compete at the Olympics, despite the body having deemed that she was guilty of three whereabouts failures.
Briton Armitstead, who took silver in the London 2012 road race, was cleared by the Court of Arbitration for Sport (CAS) to compete in Rio after she successfully argued that procedures were not properly followed in the first instance where she could not be located for testing.
UKAD chief executive Nicole Sapstead said in a statement: "Ms Armitstead chose not to challenge the first and second Whereabouts Failures at the time they were asserted against her.
"At the CAS hearing, Ms Armitstead raised a defence in relation to the first Whereabouts Failure, which was accepted by the Panel. We are awaiting the Reasoned Decision from the CAS Panel as to why the first Whereabouts Failure was not upheld.
"The collection of Whereabouts information plays a key role in delivering a robust anti-doping programme. Knowing where an athlete is, and what their movements are, is a vital component of our intelligence-led testing programme and ensures that effective and unannounced out-of-competition testing can be conducted at any time, in any place, 365 days a year."
Armitstead, who was facing the prospect of a lengthy ban, released a statement following the CAS ruling in which she underlined her commitment to competing as a "clean athlete".
The 27-year-old cited an "administration" issue, which was said to have occurred when a doping official failed to locate her hotel room and could not reach her by phone, though Armitstead was tested in competition the next day.
"I understand how important it is to be vigilant in my role as a professional athlete and realise the potential implications this could have had," her statement continued.
"I would like to thank British Cycling and the team around me for all of their help and support. I am very much looking forward to putting this situation behind me and firmly focusing on Rio again after what has been an extremely difficult time for myself and my family."