Wiggins in 2012 became the first British Tour de France winner and Froome has since inherited the Team Sky leadership and won the maillot jaune three times in the last four years.
Data stolen by hackers from files held by the World Anti-Doping Agency showed Wiggins received three therapeutic use exemptions (TUEs) for anti-inflammatory drug triamcinolone – a substance which has a history of abuse in cycling and is otherwise banned – on the eve of the 2011 and 2012 Tours and 2013 Giro d’Italia.
Wiggins and Team Sky principal Sir Dave Brailsford, the British Cycling performance director until April 2014, have strenuously denied any wrongdoing, insisting each time the TUEs were medically necessary to deal with a pollen allergy that aggravates Wiggins’ long-standing asthma condition.
Froome said: “I was surprised, it was the first that I had heard of them.
“I had seen Bradley Wiggins using his inhalers so I knew he had asthma, but I wasn’t aware of his allergies.
“Without knowing the exact details of his medical condition, it’s impossible to say if he was operating in a grey area.”
The route for the 104th edition of the Tour de France was revealed yesterday, with the race set to visit all five of France’s mountain ranges for the first time in 25 years.
The Col d’Izoard represents the final summit finish, before the penultimate day’s time-trial in Marseille, which finishes inside the Stade Velodrome football arena, all of which should favour the defending champion.
“It’s definitely going to be a climbers’ race from what I can tell,” said Froome, who was at the route unveiling in Paris.
Mark Cavendish will have chances to add to his 30 stage victories – second to Eddy Merckx’s 34 – with nine stages for the sprinters on a 3,516 kilometres route that begins in Dusseldorf, Germany, with a 13km time-trial.