Team Sky have conceded “mistakes were made” over how they recorded Bradley Wiggins’ mystery treatment in the 2011 Critérium du Dauphiné but have denied ever committing any anti-doping offence. The team principal, Sir Dave Brailsford, has urged the public to accept “there is a fundamental difference between process failings and wrongdoing”.

In a belated attempt to repair their reputation Team Sky also repeated their insistence that the legal decongestant Fluimucil was in the package delivered to Wiggins in the 2011 Dauphiné, although they accepted they could not back those claims up with hard evidence.

They also forcefully denied reports they had bulk-ordered the powerful corticosteroid triamcinolone, which can help riders shed weight without losing power and said only a few of the team had been given the drug. “It is reported that as many as 70 ampoules of triamcinolone were ordered by Team Sky in 2011 alone,” it said. “This is incorrect. Our records indicate that 55 ampoules of triamcinolone were ordered by Team Sky over a four-year period between 2010 and 2013.

“Only a small proportion of this was administered to Team Sky riders. According to Dr Richard Freeman, the majority was used in his private practice and to treat Team Sky and British Cycling staff.”

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

Graham McWilliam (@grahammcwilliam) 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 (2/2)

Sky’s statement did admit that Freeman, the doctor at the heart of the controversy that threatens to bring the team to their knees, had failed to provide records to back up the claim Wiggins was given the legal decongestant Fluimucil at the 2011 Dauphiné.

Sky said Freeman’s record-keeping was the issue, and not anything more sinister, although it accepted he should have uploaded the records to a shared folder instead of keeping them on his laptop, which he reported stolen in 2014.

Sky also claimed the repeated questioning over why the former women’s coach Simon Cope would bring Fluimucil all the way from Manchester to Wiggins in 2011, when it could be bought in France, was due to a “misunderstanding”.

It added: “It is our understanding that, while Fluimucil is licensed for sale in France, the particular form used by the team (ie 3ml, 10% ampoule form for use in a nebuliser) is not available for sale in France, nor to our knowledge was it available for sale in 2011.”

In a letter to Damian Collins, the head of the culture, media and sport select committee, Brailsford said the events of recent months had “highlighted areas where mistakes were made by Team Sky”, including members of staff not complying fully with the policies and procedures that existed at that time.

He insisted: “Many of the subsequent assumptions and assertions about the way Team Sky operates have been inaccurate or extended to implications that are simply untrue. Our mission is to race and win clean and we have done so for eight years.”

Sky’s Geraint Thomas increased the pressure on his former team-mate Bradley Wiggins and Freeman by saying it was “annoying” he and other riders were having to deal with the flak they created. Thomas, who was the first Sky rider to tweet his support for Brailsford on Monday night before another 15 team-mates in what appeared an orchestrated move, was speaking before the Tirreno-Adriatico in Lido di Camaiore.

“Freeman and Brad don’t seem to be having too much of the flak, really. It just seems to be us which also is annoying,” he told Cyclingnews. “They’re the people that this whole thing involves and they can swan around getting on with their lives while we’re the ones who have to stand here and answer these questions, which we’ve got nothing to do with. That’s annoying.”

Sixteen of Sky’s 28 riders publicly backed Brailsford in the wake of reports that some riders believed he could not carry on as the head of the team. However, the three-times Tour de France winner, Chris Froome, was not among them.

Thomas also said he fully backed Brailsford, adding: “I’ve known Dave a hell of a long time now and I’ve 100% confidence he’d never do anything the wrong way. I just believe he hasn’t done anything untoward, really, and the same with Brad and Freeman, really, as far as I know, no rules have been broken. I’m fully behind Dave.”

However, he conceded that there were still questions to be answered by Ukad’s ongoing investigation but added: “I think with Dave as well it’s like a CEO of a company, they don’t oversee everything everybody does. They’ve got to delegate and trust people to be the head of those certain areas.”