The report entitled Operation Echo said that in 2011 British Cycling collected samples from elite riders and screened them for nandrolone as part of a study into the potential contamination of supplements.

The report finds British Cycling did not follow rules in the World Anti-Doping Code in connection to how the samples were collected and analysed.

Operation Echo found that riders' samples were collected by British Cycling staff instead of doping control officers and were not analysed at a laboratory accredited by WADA.

The report found that samples were provided by athletes on the understanding UKAD would not know the results.

During the investigation Operation Echo found that at least one UKAD employee was aware of the study and that the samples could be collected and analysed at a non-WADA accredited laboratory.

WADA's Intelligence and Investigations Department has not issued any corrective recommendations in connection with the incidents, as those involved are no longer employed by UKAD, and the organisation has put measures in place to avoid a similar incident in future.

The director of WADA’s Intelligence and Investigations Department Gunter Younger praised the "full cooperation and transparency" of both British Cycling and UKAD during the investigation.

Operation Echo investigated further allegations against British Cycling and UKAD but found no evidence to uphold them.

The first allegation was that UKAD had released individual athletes’ Athlete Biological Passport data to British Cycling in 2016.

The second was that UKAD had allowed two athletes, who were advancing a contaminated supplements defence following adverse analytical findings, to privately test the products in question, before accepting the results of the analysis at the subsequent anti-doping hearing.

In a statement British Cycling said: "While the member of British Cycling staff who coordinated the 2011 study with UK Anti-Doping left the organisation several years ago, WADA’s finding that this was supported by UKAD is in line with our own understanding of events and attaches no fault to British Cycling or to the riders involved in the study.

"We now look forward to assisting UKAD where we can in the audit of their decision-making processes planned by their interim chief executive Emily Robinson."

British Cycling went on to highlight changes it had made to its own processes in recent years including the appointment of Nigel Jones as its first chief medical officer earlier this year and the creation of a Clinical Governance Committee.

A UKAD spokesperson said in response to the report: "We welcome the findings of the WADA report, which makes no recommendations for UKAD to follow, and notes that all samples related to their investigation were negative.

"The report also notes that the employees involved in the 2011 events are no longer employed by UKAD, and praises UKAD’s “diligent cooperation and transparency” with WADA’s investigation team.

"WADA’s report focuses on matters from 2011 and on the involvement of one individual, who is no longer employed by UKAD. We acknowledge that these matters would not take place today.

"The report from WADA makes clear that the results of the testing carried out by British Cycling were all negative and notes the negative results from UKAD’s own extensive testing of British Cycling athletes at that time.

"We agree that anti-doping organisations should be held to the highest standards and we will fully consider the contents report, however WADA has not made any recommendations for action by UKAD."

The episode continues a turbulent year for British Cycling, whose former doctor Richard Freeman was found guilty in March of ordering testosterone, a banned substance, for an unnamed cyclist, by a Medical Practitioners Tribunal.

Earlier this year, WADA completed a report on UKAD, describing the agency as "extremely competent" and "high-functioning."