Christian Horner is under investigation by Red Bull following an accusation of “inappropriate behaviour”.
The PA news agency understands the allegation has been made by another member of staff for the British-based Formula One team which last year carried Max Verstappen to his third consecutive world championship.
Horner, 50, who has been Red Bull team principal since 2005, will remain in his role during the investigation. He strongly denies the accusation.
Horner said: “I completely deny these claims.”
A spokesperson for Red Bull – the Austrian energy drinks company which owns the F1 team – told PA: “After being made aware of certain recent allegations, the company launched an independent investigation.
“This process, which is already underway, is being carried out by an external specialist barrister.
“The company takes these matters extremely seriously and the investigation will be completed as soon as practically possible. It would not be appropriate to comment further at this time.”
Horner has been team principal at Red Bull since their entry into F1 19 years ago, overseeing seven drivers’ world championships and six constructors’ titles.
Red Bull won 21 of the 22 rounds staged last year, with Verstappen setting a record of 10 consecutive victories as he cruised to his third title in as many years.
Horner, who is married to former Spice Girls singer Geri Halliwell, was awarded a CBE for his services to motorsport in the New Year Honours List.
Red Bull are due to launch their latest car on February 15 ahead of the new season which starts in Bahrain on March 2.