The 50-year-old, who has been Red Bull team boss since 2005, was photographed driving his car away from his property in North London in the rain this morning. It was the first time Horner has been seen since the allegations emerged on Monday.

Red Bull - the Austrian energy drinks company which owns the team – has said it launched an independent investigation after it was made aware of the allegations.

The allegation has been made by another member of staff for the British-based team which last year took Max Verstappen to his third consecutive world championship.

The hearing is expected to take place at Red Bull's headquarters in Milton Keynes. Horner strongly refutes the accusation and said: 'I completely deny these claims.'

A source within the Red Bull team said the claims related to 'controlling behaviour'. It is alleged that this was towards a female colleague. Horner has also described the accusations as 'nuts', in a message protesting his innocence to MailOnline.

An external English KC lawyer has been appointed to investigate the complaint - made by the woman to the parent firm in Austria rather than the Red Bull team itself.

Horner’s supporters claim he is a pawn in a wider power struggle at the organisation, in a void that has come about after the death of his main ally, Dietrich Mateschitz, the soft drinks magnate, who died in October 2022.

A friend of Halliwell told MailOnline that she is 'devastated' over the allegations but will stand by him in public. 

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 was awarded a CBE for his services to motorsport in the New Year Honours List. He and Halliwell married in 2015 and have one child together, seven-year-old Montague. 

Red Bull are due to launch their latest car on February 15 ahead of the new season which starts in Bahrain on March 2.

A spokesperson for Red Bull said on Monday: '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 and his team celebrated the most dominant season in Formula One history last year, with Dutch driver Max Verstappen taking his third title in a row and Red Bull winning 21 of 22 races.

The Briton is the longest-serving team boss in Formula One and was by far the youngest when he led Red Bull into the sport in 2005.

Under him, the team have won six constructors' championships and seven drivers' titles and are favourites for another season of domination.

Should Horner have to stand down, the effect on the sport would be seismic.