TEAM Sky principal Sir Dave Brailsford has said “mistakes were made” by Team Sky relating to anti-doping and medical procedures, but that “there is a fundamental difference between process failures and wrongdoing”.

The team remains embroiled in controversy relating to a ‘mystery’ package which was delivered to then Team Sky doctor Richard Freeman at the 2011 Criterium du Dauphine – a race won by Sir Bradley Wiggins – and three therapeutic use exemptions (TUEs) granted to Wiggins in 2011, 2012 and 2013.

Yesterday, Team Sky published a letter and supporting documents sent by Brailsford to Damian Collins MP, chairman of the Culture, Media and Sport select committee, in which Brailsford reiterated his belief that the team was not guilty of breaching anti-doping rules.

Moments after the statement was published Graham McWilliam, the chairman of the Team Sky board, used Twitter to say the board remained “100% behind team and Sir Dave Brailsford” following suggestions that some riders might want the team principal to resign.

UK Anti-Doping is investigating whether the team and British Cycling violated anti-doping rules when the package, addressed to Freeman, was delivered to Team Sky at the end of the 2011 Criterium.

Brailsford has said he was told the package contained the legal decongestant Fluimucil, but as yet no documentary evidence has been produced.

It has been alleged the package instead contained the banned corticosteroid triamcinolone, the drug for which Wiggins later received TUEs for but which he would not have been permitted to use at the time. Team Sky have strenuously denied that was the case.

Last week, UK Anti-Doping boss Nicole Sapstead told the Culture, Media and Sport committee that UKAD’s investigation had found the absence of documentary evidence was because Freeman had failed to follow the team’s record-keeping policy and had his laptop stolen in 2014.

In his letter, Brailsford wrote: “Self-evidently, the events of recent months have highlighted areas where mistakes were made by Team Sky.

“Some members of staff did not comply fully with the policies and procedures that existed at that time.

“Regrettably, those mistakes mean that we have not been able to provide the complete set of records that we should have around the specific race relevant to UKAD’s investigation. We accept full responsibility for this.

“However, many of the subsequent assumptions and assertions about the way Team Sky operates have been inaccurate or extended to implications that are simply untrue.

“There is a fundamental difference between process failures and wrongdoing. Our commitment to anti-doping has been a core principle of Team Sky since its inception. Our mission is to race and win clean, and we have done so for eight years.”

Following publication of the letter, McWilliam used Twitter to state the Team Sky board’s support for Brailsford following Monday’s Cycling News report which said unnamed riders on the team were considering asking him to resign.

“Pleased to see @TeamSky challenging some of the inaccurate commentary of recent days...” McWilliam wrote.

“For record, TS Board & Sky are 100% behind team and Sir Dave Brailsford as its leader. We look forward to many more years of success”

Several riders, led by Geraint Thomas, used Twitter to express their own support for Brailsford. As of last night, there had been no public comment from three-time Tour de France winner Chris Froome.

Thomas told Cycling Weekly it was “annoying” and “frustrating” that the team’s riders were being asked to answer for the actions of others.

“I know as much you guys really,” Thomas said.