Helmut Marko admits he is “flabbergasted” that texts allegedly from Christian Horner to the complainant involved in Red Bull’s investigation were leaked to F1 personnel and media.

Red Bull F1 boss Horner was cleared on Wednesday of “inappropriate behaviour” after a three-week internal probe, conducted by an external lawyer, following allegations from a female colleague which Horner strongly refuted.

But late on Thursday, WhatsApp texts and pictures – some of a sexually suggestive nature – were leaked from an anonymous source to over 100 F1 personnel and media, allegedly showing conversations between Horner and the complainant. The veracity of the content cannot be verified and it is not known whether the alleged exchanges formed part of the investigation or whether it is new evidence.

Now Red Bull senior adviser Marko, who was in conversation with Horner in the F1 paddock in Bahrain on Thursday ahead of the first race of the new season, has reacted to the leak.

"I’m flabbergasted and surprised that the documents were leaked,” he told German outlet Bild, as reported by motorsport-total.

“I’ve never seen them myself.”

Horner responded to the latest development with a short statement on Thursday night: “I won’t comment on anonymous speculation, but to reiterate, I have always denied the allegations. 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 Independent contacted Red Bull GmbH, Red Bull Racing’s parent company, for further comment to which they replied: “This is a private matter between Mr Horner and another and it would be inappropriate for Red Bull to comment on this.”

Horner could yet find himself in hot water with the sport’s governing body, the FIA, with the governing body’s president Mohammed Ben Sulayem set to discuss the matter with F1 chief executive Stefano Domenicali on Friday in Bahrain.

All those who participate in Formula 1 must abide by a set of regulations, with Article 12.2 stating that a competitor could be found in breach of the code for: “Any words, deeds or writings that have caused moral injury or loss to the FIA, its bodies, its members or its executive officers, and more generally on the interest of motorsport and on the values defended by the FIA.”

Mercedes boss Toto Wolff and McLaren CEO Zak Brown had, earlier on Thursday, called for F1 and the FIA to review the investigation conducted by Red Bull.

“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 Independent contacted Red Bull GmbH, Red Bull Racing’s parent company, for further comment to which they replied: “This is a private matter between Mr Horner and another and it would be inappropriate for Red Bull to comment on this.”

Horner, whose wife is Spice Girl pop star Geri Horner, could yet find himself in hot water with the sport’s governing body, the FIA, with Ben Sulayem set to discuss the matter with Domenicali on Friday in Bahrain.

All those who participate in Formula 1 must abide by a set of regulations, with Article 12.2 stating that a competitor could be found in breach of the code for: “Any words, deeds or writings that have caused moral injury or loss to the FIA, its bodies, its members or its executive officers, and more generally on the interest of motorsport and on the values defended by the FIA.”

Mercedes boss Toto Wolff and McLaren CEO Zak Brown had, earlier on Thursday, called for F1 and the FIA to review the investigation conducted by Red Bull.

It is understood that neither F1’s American owners Liberty Media, nor its regulator the FIA, has seen Red Bull GmbH’s report into Horner which is thought to stretch to 150 pages – and was said to be “confidential”.

The Red Bull F1 chief, 50, is the longest-serving team principal on the F1 grid, having been at the helm since the team’s inception in 2005.