The British Olympic Association have been accused of "wasting a lot of time and money" by the World Anti-Doping Agency after their failed court case to keep their lifetime ban for drugs cheats.
The BOA took WADA to the Court of Arbitration for Sport in a bid to keep the ban but were defeated.
WADA director-general David Howman said on Tuesday: "At the end of the day they have wasted a lot of time and a lot of money and got the inevitable result."
Howman said the BOA had a deadline of May 18 to change their bylaw or face being reported to the International Olympic Committee for remaining "non-compliant" with the world anti-doping code.
Howman had earlier claimed in a New Zealand radio interview that the BOA and supporters of the lifetime ban "had been held up to ridicule like they are being by some of the world media", and in a conference call with reporters he criticised BOA chairman Lord Moynihan for describing the outcome of the court case as "a hollow victory for WADA".
"Declaring this issue a hollow victory is the wrong way of looking at it since it was a matter taken up by the BOA," added Howman. "The issue for the BOA is the rest of the world is looking at you and saying 'what have you done this for?'
"[Moynihan] has expressed views which have hardly had any touch with the real facts and the real situation in relation to anti-doping."
Howman added that the CAS judgement contained not even crumbs of comfort for the BOA.
The BOA are now pushing WADA to change the code to make it a minimum four-year ban for a first serious offence with national Olympic committees still maintaining some autonomy to increase sanctions further.
Howman warned that that could cause legal problems, especially in relation to restraint of trade cases in courts of human rights, and that they would take independent legal advice on any proposed changes.