Team Sky are at the centre of an investigation into the contents of a package delivered to then team doctor Richard Freeman at the Criterium du Dauphine race in France in 2011 for rider Bradley Wiggins, who went on to win the 2012 Tour de France.
"There was a Team Sky policy of doctors keeping records. And other doctors did. But there were zero records from Freeman at this race," Nicole Sapstead, chief executive of the anti-doping body, told the British Parliament's select committee on culture, media and sport.
Team principal Dave Brailsford told the committee in December that Freeman had informed him that the package contained Fluimucil, a legal decongestant.
Sapstead said UKAD could not confirm or disprove that the package contained Fluimucil.
Team Sky said in a statement that they were confident there had been no wrongdoing.
"Team Sky is a clean team. We abide by the rules and we are proud of our stance against doping," they said.
Freeman, who works for British Cycling but at the time held a dual role at Team Sky and the national governing body, pulled out of his scheduled hearing on Wednesday because he was "too unwell" to attend.
British Cycling issued a statement acknowledging serious failings in its record keeping.
"Our medicines management processes have been reviewed several times since 2011 and, through working with UKAD in recent months, we have identified further areas for improvement on this and in the provision of our wider medical services," the statement said.
The governing body added that it would be auditing its medical services and reviewing its medicines management policy.
"At British Cycling, we are wholly committed to clean sport and I want to assure athletes, fans and all other stakeholders that this commitment is unwavering," British Cycling chair Jonathan Browning said.
The Committee published a letter from the Medicines and Healthcare Products Regulatory Agency which said Fluimucil was an unlicensed medicine at the time it was obtained by Freeman.
The agency said doctors supplying unlicensed medicines in Britain would need to keep a record of the source of the drug as well as the dates it was obtained and supplied.
(Reporting by Julien Pretot and Toby Davis, editing by Ed Osmond)
