Paris  - Lance Armstrong could face punishment by the French anti-doping agency (AFLD) over his behaviour during a doping test last month in southern France.

Samples taken from the seven-time Tour de France winner on March 17 in Beaulieu-sur-mer returned negative but it is alleged that he may have violated the AFLD's rules regarding observation due to his lack of cooperation with the tester.

The 37-year-old Astana rider made the AFLD accredited doctor wait 20 minutes before allowing him take a blood, hair and urine sample.

Although the tests returned negative, the AFLD said in statement Thursday that following talks with the ruling International Cycling Union (UCI) that it would be within its rights to sanction Armstrong over his behaviour, but did not indicate whether it would.

The AFLD said in the statement that Armstrong had failed to "respect the obligation to remain under the direct and permanent observation" of the tester.

Armstrong, who is due to ride in this year's Tour de France, has denied any misbehaviour.

"I had never heard of labs or governments doing drug testing and I had no idea who this guy was or whether he was telling the truth," Armstrong said in a statement.

"We asked the tester for evidence of his authority. We looked at his papers but they were far from clear or impressive and we still had significant questions about who he was or for whom he worked."

"I was there with [Astana team manager] Johan Bruyneel and two other people. We told the tester we wanted to check with the UCI to confirm who he was and to make sure he wasn't just some French guy with a backpack and some equipment to take my blood and urine."

Armstrong revealed that the test was the 24th unannounced doping control he had been subjected to since announcing his comeback to the sport last October.

The AFLD has previously asked Armstrong to allow frozen urine samples taken in 1999 to be re-tested to finally put to rest unsubstantiated rumours that he had been involved in doping but the cyclist has so far refused.

Armstrong is currently recovering from a broken collarbone sustained following his fall in the Vuelta Castilla y Leon race in Spain on March 25 but following surgery is confident of being able to return for next month's Giro d'Italia which starts on May 9. (dpa)