British cyclist Bradley Wiggins has defended his use of banned substances under medical exemption rules, saying he was not looking for “unfair advantage” but merely trying to mitigate the impact of asthma and allergies.

The first Briton to win the Tour de France, Wiggins has been the subject of allegations of hypocrisy over the timing of the medical interventions since his anti-doping records were among those leaked by cyber hackers on fancybear.net website.

The data leaked relates to Therapeutic Use Exemptions (TUEs), which allow athletes to take banned substances for verified medical needs and are signed off by sports federations.

There is no suggestion Wiggins has broken any rules.

The data revealed Wiggins was given permission to take the powerful corticosteroid triamcinolone before his breakthrough triumph at the 2012 Tour de France as well as the 2011 version of the endurance classic and the 2013 Tour of Italy.

“This was to cure a medical condition. This wasn’t about trying to find a way to gain an unfair advantage,” Wiggins told BBC TV.

“This was about putting myself back on a level playing-field in order to compete at the highest level on tour.”

Wiggins’s former doctor at the Garmin Slipstream team, Prentice Steffen, told the BBC on Friday he was “surprised” the cyclist had needed triamcinolone, which convicted dopers David Millar and Michael Rasmussen said was a highly potent drug.

The 36-year-old said he had been struggling with his breathing before the 2012 Tour de France and decided to take triamcinolone on medical advice.

“It was prescribed for allergies and respiratory problems,” Wiggins added.

“I’ve been a lifelong sufferer of asthma and I went to my team doctor at the time and we went in turn to a specialist to see if there’s anything else we could do to cure these problems.

“And he in turn said: ‘Yeah, there’s something you can do but you’re going to need authorisation from cycling’s governing body’.”

A fifth batch of documents relating to more than 40 athletes was published by cyber hackers on Friday.

The World Anti-Doping Agency (WADA) has said it believes the hackers are Russian.

WADA said the hackers had gained access to its anti-doping administration and management system (ADAMS) via an IOC-created account for last month’s Rio Olympic Games.