Britain's David Millar has jumped to the defence of Italian rival Alessandro Petacchi, who was axed from the Tour de France after testing positive for salbutamol.

Petacchi returned the "non negative test" during the recent Giro D'Italia and has been provisionally suspended by his team Milram and charged with doping by the Italian Olympic Committee.

Milram general manager Gerry van Gerwen said: "We've signed the ProTour's ethical code and by virtue of this code a rider suspected of resorting to doping cannot compete in a race."

Petacchi is a registered asthmatic and has a certificate which allows for restricted use of salbutamol, a substance primarily fond in asthma medication.

Petacchi argued that any overuse was an oversight but he is facing a possible one-year ban.

Millar's Saunier Duval team-mate Leonardo Piepoli has also been suspended after testing positive for salbutamol during the Giro.

And Millar, who is back competing after serving a two-year ban for using EPO, insisted both men were "undeservedly being punished".

Millar said: "Piepoli is a rider I have a huge amount of respect for and trust as a cyclist. He is going through an horrific time at the moment and I think it is very sad what he and Petacchi are having to experience.

"It seems very strange. That control is such an odd one.

"There is no way Piepoli would have injected salbutamol or used it to dope to cheat.

"It is ironic that a guy who I have got a lot of respect for - he is a grande monseur - is getting punished when there are many of guys out there aren't getting and they deserve to be."

Millar insists he will always give the benefit of the doubt to athletes but he has not made a habit of defending suspected cheats since his return to action.

Cycling's credibility has gone through the floor after the scandals of the last 14 months and, given his past, Millar feels a responsibility to try and mend the sport.

This year's Tour de France is without a defending champion for the first time in its 104-year history as Floyd Landis battles to convince the world he is not a dope cheat.

Landis tested positive for abnormal levels of testosterone after winning last year's Tour. He has appealed to the American anti-doping body, who could make a ruling on Friday.

As a result of the scandals, cycling's governing body UCI has insisted upon every rider signing an anti-doping declaration and they cannot compete in the Tour without doing so.

The document begins with a declaration that the rider has not been involved in any past doping and demands they pledge a year's salary in the event of returning a positive test in the future.

The introduction of the charter met with stiff opposition from many teams. CSC and Quickstep waited until today as a show of opposition and were the last teams to sign up.

A spokesman from CSC explained: "The fight against doping takes more than just signing a piece of paper. It takes action. It needs a change in culture.

"That is what we want to see, not all the riders being taken hostage by some media stunt.

"There will always be cheaters. If people seriously want to cheat they will take the risk. They will try to find the hole in the system so we must make the system better."

Millar understands the opposition but accepts extreme measures are necessary if cycling is to escape the shadow of doping.

"It's unfortunate that we've had to get to that point where we're signing contracts that even a first year law student would say 'don't ever go near'.

"But we have no choice. It's a show of will and unity.

"I don't think any of us can escape the doping problems that go on in cycling.

"We have to look to the future but we can't move into the future without dealing with the past and we have a pretty serious past we have to face up to.

"It is only now that people are admitting to things they got up to. Not a day goes by when I don't think about the bigger picture.

"All of us have a responsibility, especially my generation, to make sure the young cyclists coming through don't have to deal with our baggage because I don't think that is fair to them."