Staut has made a counter claim disputing the accusation and also lodged papers with the FEI.

The argument was alleged to have taken place at the Novotel Hotel in Bordeaux where both had been attending a party held in conjunction with "Le Jumping International de Bordeaux", an indoor event at the Bordeaux Exhibition Centre.

The argument is said to have escalated after Valdar Longem took a mobile phone belonging to Staut.

A scuffle followed when he attempted to retrieve it.

Valdar Longem's report to the FEI claimed that she had been headbutted "full in the face", suffering concussion and nose bleeds.

Her evidence is understood to be supported by medical certificates.

She alleged that Staut had left the hotel room after the incident without checking on her condition.

The FEI have confirmed that they had received reports from both parties in accordance with their "safeguarding policy against harassment and abuse". 

Reports of the incident are also understood to have been filed with the French Equestrian Federation and the French police by Vadar Longem's legal representatives.

Valdar Longem is said to have attempted to report to the French police herself, but was unable to do so because an interpreter was unavailable.

She is understood to have returned to Olso, where she made a report to Norwegian authorities.

"Marie has been affected both personally and as an athlete by these unspeakable acts of violence," a statement issued by Valdar Longem’s lawyer Antoine Levy said.

"She is pressing charges because she is the only victim here and wants to make sure that similar incidents will not happen to other people in the future.

"Her actions through FEI are important to safeguard that the sport is a safe arena to herself and other women for the future, she relies on FEI to also conduct a thorough investigation of the matters.

"Learning that her aggressor is now claiming to be a victim defies understanding." 

Staut told the French newspaper L’Equipe that he "disputes these accusations" and that he "was violently verbally and physically assaulted in a private context".

"The complainant’s claims are formally contested by Kevin Staut," his lawyer Carole Guillemin said in a statement reported by worldofshowjumping.com 

It claimed that Staut had left the hotel room "to avoid the situation getting out of hand".

Staut was also examined for a meniscal tear in his knee, though it was not made clear if this was as a result of the hotel incident.