Sir Bradley Wiggins and Chris Froome have medical files leaked in latest 'Fancy Bears' hack

Sir Bradley Wiggins and Chris Froome are among five Britons to have had their medical files stolen from the World Anti-doping Agency [Wada] and released by Russian hackers.

Following Tuesday's (13 September) leak of personal files of several high profile American athletes, including tennis stars Serena Williams and Rio 2016 gymnast star Simone Biles, Wada has confirmed another leak following a hack into its confidential database.

The cyber-espionage group behind the attack, Fancy Bears claims its mandate is to "expose the athletes who violate the principles of fair play by taking doping substances".

It names 25 more athletes from eight different countries, including 2016 Tour de France champion Froome and five-times Olympic gold medallist Wiggins, and fellow Britons Charley Hull, Heather Fisher and Sam Townsend.

"Wada is very mindful that this criminal attack, which to date has recklessly exposed personal data of 29 athletes, will be very distressing for the athletes that have been targeted; and, cause apprehension for all athletes that were involved in the Rio 2016 Olympic Games," Wada director general Olivier Niggli said in a statement that did not name the latest athletes to be implicated.

"To those athletes that have been impacted, we regret that criminals have attempted to smear your reputations in this way; and, assure you that we are receiving intelligence and advice from the highest level law enforcement and IT security agencies that we are putting into action."

The hackers claim to have illegally gained access to Wada's administration and management database via an International Olympic Committee account created for the Rio 2016 Games.

The allegations specifically relate to the use of TUEs – therapeutic usage exemptions – which permit banned substances to be taken on medical grounds. The group describes the use of TUEs as "licences for doping".

The documents suggest Froome was given a TUE for prednisolone, used to treat a variety of inflammatory and autoimmune conditions and some cancers for a five-day period for at the Critérium du Dauphiné in May 2013 and a seven-day period at the Tour of Romandie in April 2014.

Wiggins meanwhile is claimed to have used a number of TUEs dating back to 2008, including formoterol and budesonide, used for asthma treatment.

British Cycling have since condemned the disclosure of confidential information with Team Sky rider Froome saying he has "no issues with the leak."