The female Red Bull employee at the centre of allegations against Christian Horner has lodged an official complaint to Formula 1's governing body the FIA, the BBC reported on Saturday.

Allegations of inappropriate behaviour against Red Bull's embattled team principal have overshadowed the opening weeks of the 2024 F1 season.

Horner was cleared of wrongdoing by an internal investigation carried out by Red Bull's parent company last month.

However, the saga has not ended there as an anonymous email was sent to Formula One staff and media the next day containing alleged messages from Horner to a female member of the team.

Red Bull then suspended the employee at the centre of the allegations.

However, she has now appealed that suspension with Red Bull GmbH, the parent company of the Formula One team.

Horner has guided Red Bull to six constructors' championship wins and seven drivers' title triumphs since 2005, including the last three won by Max Verstappen.

But the star driver's father, Jos Verstappen, claimed earlier this month that Red Bull faced being "torn apart" if Horner remained in his position.

In a statement to AFP, the FIA said: "Enquiries and complaints are received and managed by the compliance officer, and the ethics committee where appropriate.

"Both bodies operate autonomously, guaranteeing strict confidentiality throughout the process. As a consequence, and in general, we are unable to confirm the receipt of any specific complaint."

Horner, 50, has always denied the claims made against him.

He was accompanied by his wife — the former Spice Girls pop star Geri Halliwell — at the first two Grand Prix races this season.

"There was a grievance that was raised, it was dealt with in the most professional manner," said Horner ahead of the Bahrain Grand Prix.

"An independent KC (King's Counsel), that is one of the most reputable KCs in the land, and he took time to investigate fully all of the facts.

"He interviewed all of the people involved as well as others of interest. He looked at everything and he came to the conclusion where he dismissed the grievance.

"As far as I am concerned, and as far as Red Bull are concerned, we moved on and we look to the future. The time now is to draw a line under it."

On the track, the season has started far more smoothly for the defending world champions.

Verstappen has finished ahead of team-mate Sergio Perez for one-two victories in the opening races of the year in Bahrain and Saudi Arabia.