Team Sky is the focus of a UKAD investigation into the contents of jiffy bag delivered to team doctor Richard Freeman at the 2011 Criterium du Dauphine for Bradley Wiggins.
"There was a Team Sky policy of doctors keeping records," Nicole Sapstead, chief executive of the anti-doping body, told the British Parliament's select committee on culture, media and sport select.
"And other doctors did. But there were zero records from Freeman at this race," she said.
Team Sky boss Dave Brailsford relayed to the committee in December that Freeman told him the jiffy bag - specially flown over with then British cycling coach Simon Cope - contained Fluimucil, a legal decongestant available in France where the team was racing.
Sapstead said it was not possible for UKAD to determine if the package did contain Fluimucil because of incomplete record-keeping in this instance.
This comes on top of Richard Freeman pulling out of his scheduled hearing yesterday who stated he was too unwell to attend.