An anonymous email was distributed to selected media figures, including Speedcafe’s F1 editor, midway through second practice for this weekend’s Bahrain Grand Prix.

It follows Horner being cleared of the allegations against him, a finding announced on Wednesday (local time).

The email was sent multiple times. The veracity and authenticity of the information contained within the email has not been verified or confirmed by Red Bull or Horner.

The Red Bull Racing team boss issued a personal statement on the matter.

“I won’t comment on anonymous speculation, but to reiterate, I have always denied the allegations,” he said.

“I respected the integrity of the independent investigation and fully cooperated with it every step of the way.

“It was a thorough and fair investigation conducted by an independent specialist barrister and it has concluded, dismissing the complaint made.

“I remain fully focused on the start of the season.”

The sustained attack on Horner, following the resolution of the investigation, suggests a deliberate attempt to assassinate the 50-year-old’s character.

The timing of the email is curious and was clearly deliberate. The list of recipients includes not just Formula 1 journalists but entertainment reporters in a move clearly designed to cause maximum damage.

It also included a number of email addresses that would not be widely available and were, in some instances, personal accounts.

Earlier, rival team bosses had called for transparency over the investigation, with Zak Brown suggesting it’s something the FIA should investigate.

“My personal opinion is we can’t really look behind the curtain,” said Mercedes’ Toto Wolff of the situation, prior to the email leak.

“At the end of the day, there is a lady in an organisation that has that has spoken to HR and said there is an issue and it was investigated and yesterday, you know, the sport has received the message, it’s all fine, we’ve looked at it.

“I believe that with the aspiration as a global sport on such critical topics it needs more transparency and I wonder what the sport’s position is.

“We are competitors, we are a team, and we can have our own personal opinions or not, but it’s more like a general reaction or action that we as a sport need to assess what is right in that situation and what is wrong.”

Brown added of the Red Bull GmbH statement: “I think from what I’ve seen there continues to be a lot of rumours and speculation, questions. I think the sanctioning body has a responsibility and authority to our sport to our fans.

“I think all of us in Formula 1 are ambassadors for the sport on and off the track, like you see in other sports and so I think they need to make sure that things have been fully transparent with them.

“I don’t know what those conversations are and it needs to be thorough, fully transparent, and that they come to the same conclusion that has been given by Red Bull and that they agree with the outcome.

“But I think until then, there’ll continue to be speculation because there are a lot of unanswered questions about the whole process, and so I think that’s what’s needed by those that run the sport to really be able to draw a line under it.

“Until then, I think there’ll continue to be some level of speculation by people, and I don’t think that’s healthy for the sport.”

Horner has headed Red Bull Racing since 2005 when the drinks company purchased what was the Jaguar Racing team, installing the Englishman as its boss.

In the nearly two decades since, Horner has overseen more than 100 race wins, seven drivers’ championships and six constructors’ titles, making him one of the most successful team bosses in the sport’s history.