It says its experts have "questions" over Sergio Henao's test results - meaning he will now undergo an "altitude research programme".

The decision to withdraw him from its races comes after a monthly "internal process which looks at each rider's physiological profile".

Italian newspaper Gazzetta dello Sport has quoted Henao's agent as saying the rider recorded "anomalous values".

The tests, introduced by anti-doping authorities this winter, were all carried out at altitude.

Team Sky principal Sir Dave Brailsford said the results needed to be understood better before any judgements could be made.

"We contacted the relevant authorities - the UCI (International Cycling Union) and CADF (Cycling Anti-Doping Foundation)] - pointed to these readings and asked whether they could give us any insights," he explained.

"We've also taken Sergio out of our race programme whilst we get a better understanding of these profiles and his physiology.

"We want to do the right thing and we want to be fair.

"It's important not to jump to conclusions."

Sergio Henao was born at altitude in Rionegro, Colombia and lives and trains in the region ©teamsky.com via Getty Images


Henao was born at altitude in Rionegro, Colombia, and lives and trains in the region outside the race season.

He returned there in October and had World Anti-Doping Agency (WADA) accredited out-of-competition tests.

Sir Dave added: "Sergio was raised in the mountains, goes back in winter and lives and trains at different levels.

"We've looked as far as we can at the effects of this, but our own understanding is limited by a lack of scientific research into 'altitude natives' such as Sergio.

"We are commissioning independent scientific research to better understand the effects of prolonged periods at altitude after returning from sea level, specifically on altitude natives.

"The independent experts are looking to use WADA-accredited laboratories and Team Sky will make the data and findings available to WADA, the UCI and CADF.

"Sergio will help with this programme and we expect him to be out of the race schedule for at least eight weeks.

"Once we have completed our assessment, we'll decide on the right steps and give a full update."

David Howman said Henao's profile on his biological passport would help shed light on the under-question test results ©AFP/Getty Images





Speaking here after giving a presentation on the opening day of the Tackling Doping in Sport conference, WADA director general David Howman said: "You have to be aware that if samples were taken at altitude, that's where they were taken.

"The issue I think we would want to have a look at, or even talk to Team Sky about, is is this a [biological] passport issue?

"We'd want to see the [athlete's] profile.

"No one at WADA has seen the profile.

"I would think they would share it."

He added: "There's been a lot of research into what affect altitude training has.

"There can be reasons for a discrepancy in a profile."

Team Sky, a British team, has enjoyed huge success since it was founded in 2009, winning the last two Tour de France with Bradley Wiggins in 2012 and Chris Froome in 2013.

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