Colombian rider Nairo Quintana, whose Tour de France team are targeted in a doping investigation, said he had "nothing to hide" after two unnamed members of the French outfit were briefly detained before being released.

Quintana, 30, leader of the Arkea-Samsic team and winner of the 2014 Giro d'Italia, said no drugs were discovered during the investigation.

"No doping substance has ever been found," Quintana said in a statement.

"I have nothing to hide and have never had anything to hide."

Police detained two people from the Arkea-Samsic team on Monday, with press reports saying they were a doctor and physiotherapist.

The probe is the first significant one in several years for the repeatedly scandal-hit tour
The probe is the first significant one in several years for the repeatedly scandal-hit tour POOL / Stuart Franklin

Marseille prosecutor Dominique Laurens said the pair, whom he had said had "many health products including drugs in their personal belongings, but also and above all a method that can be qualified as doping", had both been released Tuesday.

"The investigation is ongoing," Laurens said, adding that new developments were possible.

"Investigations and hearings (must) be carried out before the public prosecutor reaches a decision on the basis of the elements collected."

A source familiar with the matter told AFP that searches had targeted several riders including Quintana's brother Dayer, as well as members of the medical team.

Nairo Quintana finished the Tour in 17th place, more than an hour behind winner Tadej Pogacar. Quintana's teammate Warren Barguil was in in 14th place.

It is the most significant investigation in years for the repeatedly scandal-hit Tour, which wrapped up Sunday in Paris with a surprise victory for 21-year-old Slovenian debutant Pogacar, the youngest winner in more than a century.

Nairo Quintana, 30, won the Giro d'Italia in 2014
Nairo Quintana, 30, won the Giro d'Italia in 2014 AFP / KENZO TRIBOUILLARD

The Tour was rocked by a major probe in 1998, when customs officials stopped a vehicle laden with doping products and the Festina team was thrown off the race as the peloton headed into Paris.

Most notoriously, Lance Armstrong, who won from 1999-2005, admitted doping in 2013 and the American was stripped of his record seven titles.

The French team's general manager Emmanuel Hubert told AFP the probe involved only "a very limited number of riders, as well as their close entourage who are not employed by the team".

"But if it turned out that at the end of the current investigation, elements confirm the truth of doping practices, the team would immediately dissociate itself from such acts and would take the necessary measures without delay," Hubert said.

He added that the investigation "does not target the team or its staff directly".

Hubert added in a statement Wednesday that two riders had been interviewed as witnesses and "at the end of this hearing they had been able to return to their home, while being free to be able to exercise their profession as professional cyclists without any restriction".

The probe will have come as a huge disappointment to organisers after positive headlines about the against-the-odds organisation of the race and the drama that saw Pogacar seize victory late in the race.

Many had predicted the Covid-19 pandemic would prevent the riders making it the 3,400 kilometres (2,100 miles) from the Mediterranean city of Nice to the French capital.

The prosecutor's statement said the investigation was focused on the prescription of a substance or banned method for athletes, as well as help and encouragement in its use.

The charges can lead to up to five years in prison and a 75,000-euro ($88,000) fine.