MONTREAL • The World Anti-Doping Agency (Wada) has called on Russia to do all it can to stop a series of hacks of star athletes' medical records, as the Kremlin said it was ready to help.

"We condemn this criminal activity and have asked the Russian government to do everything in their power to make it stop," said Olivier Niggli, Wada's director-general.

He said the hack on Wada's computer system constituted "retaliation" against the agency, which imposed heavy penalties against Russia over doping, including banning practically its entire athletics team from the Rio Olympics.

Russia denied involvement in the hacks but said it was ready to help.

"If we're talking about a request for help, then no question, if we receive such an appeal," Kremlin spokesman Dmitry Peskov said.

"Russia consistently backs fighting cybercrime, consistently invites all states and international organisations to cooperate in this area, and this position of Russia is well known."

On Tuesday, Wada announced that the Russian cyber-espionage group Tsar Team (APT28), also known as Fancy Bears, had broken into its Anti-Doping Administration and Management System (Adams) database.

The hacking group released information gleaned from the files of sports stars, including US Olympic gymnast Simone Biles and tennis champions Venus and Serena Williams.

In a fresh release on Wednesday, the group published confidential data of 25 athletes, from eight countries, including British cyclists Bradley Wiggins and Chris Froome, whose three Tour de France triumphs followed that of Wiggins.

"To those athletes that have been impacted, we regret that criminals have attempted to smear your reputations in this way," said Niggli.

Russia's Sports Minister Vitaly Mutko brushed aside suggestions of an orchestrated hacking campaign.

"How can you prove that they are hackers from Russia? You blame Russia for everything," he said.

As Wada urged Russian help, Niggli warned that the hacking could hamper the country's efforts to reintegrate into the sports world.

Froome and Wiggins defended their use of therapeutic use exemptions (TUEs).

Froome said that he had "no issues" with the leaks, pointing out he has spoken publicly about being granted TUEs before.

The 31-year-old told the Scotsman newspaper this summer that he had used TUEs twice during his career - in 2013 and 2014.

A statement on behalf of Wiggins was similarly issued, which stated: "There's nothing new here. Everyone knows Brad suffers from asthma, his medical treatment is British Cycling and International Cycling Union approved and like all Team GB athletes he follows Wada regulations to the letter.

"The leak of these records is an attempt to undermine the credibility of Wada and that's something for them to deal with."

AGENCE FRANCE-PRESSE, THE GUARDIAN