Thursday, 12 July 2012:

Tour de France leader Brad Wiggins has again vehemently denied doping as some critics question how he is so good.

Wiggins and his powerful Sky team are coming under increasing scrutiny, with some sections of the French press deriding them as "UK Postal".

That is a reference to Lance Armstrong's team, which was known as US Postal for some of his seven Tour de France titles.

Armstrong is now fighting US Anti-Doping Agency charges.

"There's one reason I'm in this position and that's because I've worked hard," Wiggins said.

It was revealed on Wednesday that Sky are investigating the past of consulting team doctor Geert Leinders.

He worked with Rabobank when they were hit by two doping scandals and left the Dutch team in 2009.

General manager Dave Brailsford insists Leinders has done nothing wrong at Sky but acknowledges there could be a risk to the team's reputation.

French police also arrested Tour rider Remy Di Gregorio on Tuesday as part of a doping investigation.

Speaking on Wednesday, Wiggins again expressed frustration that some critics were questioning his performances.

It followed his profane-laden outburst three days previously when he lashed out at anonymous comments on the internet.

Asked why he had spoken so strongly on Sunday, Wiggins replied: "To me it's them (critics) pissing all over everything I've done, by saying, 'yeah, he's cheating'."

Wiggins and Sky officials have repeatedly referred to his steady progression through the sport for more than a decade.

"I don't feel that I should have to sit here and justify everything I've done to the world," he said.

"I'm not just some s*** rider who's come from nowhere.

"I've been six-times world champion (on the track), fourth in the Tour de France, third in the Vuelta.

"I've got an incredible pedigree behind me."

Wiggins added he had passed dozens of anti-doping tests.

"I'm tested by the UCI (International Cycling Union) God knows how many times a year, God knows how many times on this race and the Dauphine (race), blood tested every morning," he said.

"What more can I do? I don't know really. I'd love to know."

The speculation about Wiggins and Sky went up a level after the team dominated the uphill finish on stage seven, a performance that put him into the yellow jersey as race leader.

It is in stark contrast to the atmosphere at last year's Tour, where Cadel Evans' win and his titanic duel with the Schleck brothers was hailed as evidence that the sport was cleaning up its act.

AAP