The family of Tour de France winner Floyd Landis has signs outside their Pennsylvania home supporting their son and thanking God. But the U.S. rider's team said on Thursday (July 27) that tests showed unusual levels of testosterone. If Landis's B sample confirms the result, the 30-year-old is certain to be stripped of his victory, becoming the first Tour winner to be disqualified for doping. Landis's mother Arlene's first reaction was to say that her son is a man of honour. "I knew he was taking a pain medication. He had to. Anybody knew he couldn't function without pain. So I don't know how that would have interferred with what could be suggested that the problem is. But I remain positive that he is a man of honour and he's not proven guilty yet." Once she had spoken to her son, Arlene Landis said the test results had not been confirmed. "Floyd talked to me in a lot of discouragement because of the media press that he's getting. But, you know, the fact is that there is nothing proven that anything is wrong with his test. He said this test is so irregular, there is no reason why it wouldn't have shown up other days he was riding if that was a fact. So I'm not concerned, I think God is allowing us to go through this so that Floyd's glory is even greater." In the 17th stage, a gruelling ride to Morzine in the French Alps, Landis produced an incredible comeback a day after a disastrous showing had appeared to ruin his chances of victory. The rider from Pennsylvania crossed the line over five minutes ahead of Spaniard Carlos Sastre and went on to win the race in Paris on Sunday, succeeding compatriot Lance Armstrong who retired last year after winning the Tour a record seven times. If Landis were disqualified, Spain's Oscar Pereiro, who finished second in the overall standings, would be declared the winner.