UKAD have confirmed they were subjected to a cyber-attack ©UKAD

Russian-based cyber espionage group Fancy Bears' are suspected of carrying out an on UK Anti-Doping (UKAD) systems after the organisation confirmed it had foiled an attempt at the weekend.

In a statement, UKAD, who possess confidential medical information on thousands of athletes, insisted no data was lost or compromised during the attack.

Although the identity of the perpetrators has not been revealed, speculation has grown that it was the work of Fancy Bears' due to continued political tension between Britain and Russia.

It followed the attempted murder of former spy Sergei Skripal and his daughter in Salisbury earlier this month.

UKAD are also among the National Anti-Doping Organisations assisting with testing in Russia.

There is no indication on Fancy Bears' Twitter feed that they were behind the attack and no-one has yet claimed responsibility.

"Over the weekend UK Anti-Doping was made aware of a cyber attack affecting our systems," a UKAD statement read. 

"We can confirm that no data has been lost or compromised.

"We took the necessary steps to investigate and resolve the situation. 

"No core activity, including our testing programme, has been impacted.

"We are satisfied that we have appropriate levels of cyber security in place, and we continually review our systems and measures to ensure they are of a very high standard."

British cyclist Sir Bradley Wiggins is among the athletes to have been targeted by the Russian hacking group ©Getty Images
British cyclist Sir Bradley Wiggins is among the athletes to have been targeted by the Russian hacking group ©Getty Images

Fancy Bears have released a raft of confidential medical information in recent years on a host of high-profile athletes after it had hacked the World Anti-Doping Agency and the United States Anti-Doping Agency.

The leaks largely focused on thereputic use exemptions (TUE) in which athletes had obtained permission to take otherwise banned substances for medical reasons.

Fancy Bears' exposed athletes including British Tour de France-winning cyclist Sir Bradley Wiggins, who has been the subject of intense scrutiny in recent months following claims in a British Parliamentary report that he used the TUE system to gain an advantage.

Britain's five-time Olympic gold medallist denies the allegations. 

Athletes they have previously targeted include British athlete Sir Mo Farah, who defended both his 5,000 and 10,000 metres Olympic titles at Rio 2016.

Tennis stars Rafael Nadal and Serena Williams, four-time Rio 2016 gold medal winning gymnast Simone Biles and Tour de France winner Chris Froome - currently facing a hearing after testing positive for asthma medication salbutamol when he won the 2017 Vuelta a España - have also had their records published by Fancy Bears'.