The German Animal Welfare Federation filed a criminal complaint against the pair after their actions in the Japanese capital, but it will not result in charges.

The extreme pressure of an Olympic Games and the subsequent controversial removal of the riding discipline from modern pentathlon after Paris 2024 were cited as among the reasons for not pressing ahead with an investigation by prosecutors.

Schleu had been leading the women's modern pentathlon competition at the Olympics before the horse Saint Boy refused to jump.

Raisner was seen to repeatedly strike the horse, while Schleu faced criticism for her violent and repeated use of the whip and spurs.

Raisner was sent home from the Olympics in disgrace and later found to have broken International Modern Pentathlon Union (UIPM) rules.

Several months later, a broadcast by the Potsdam public prosecutor explained the grounds for the criminal probe's discontinuation.

"[Schleu and Raisner] only had a short-term effect on the riding horse and were in an exceptional physical and psychological situation of the Olympic competition," the public prosecutor said, as quoted by German publication Pferderevue.

"In addition, no injuries were inflicted on the competition horse.

"In view of the minor impact of the crime and against the background of the continued media reporting, it can be assumed that the investigative proceedings have had a sufficient impact on the suspects who have not yet appeared criminally."

The impending removal of riding from the modern pentathlon programme and the resultant lack of risk of a repeat incident was also referenced by the public prosecutor, who deemed it in "the public interest" to drop the criminal prosecution.

Schleu and Raisner are to make a donation to a charitable organisation, reported by Deutsche Welle to be €500 (£420/$570) in the case of the athlete and a "small sum" for the coach.

Lawyers for Schleu said this was "neither an acknowledgment of guilt on the part of Ms Schleu, nor was the guilt of our client determined or sufficient suspicion confirmed", with Raisner's representatives emphasising "our client can continue to call herself innocent".

The German Animal Welfare Association said it had aimed to initiate "a social discussion about how to deal with horses in competitive sport".

"We have undoubtedly succeeded in doing this, as the announced changes in the mode of modern pentathlon show," it said, quoted by Deutsche Welle.

The UIPM is to drop riding from the sport after the Paris 2024 Olympics, although a replacement discipline is yet to be determined.

The move and the process which led to it sparked outrage among athletes, with more than 650 signing a letter which called for the UIPM Executive Board and long-serving President Klaus Schormann, who himself is German, to resign.

The sport, which was created by modern Olympic Games founder Pierre de Coubertin and first featured at Stockholm 1912, has been left off the initial programme for Los Angeles 2028.

Along with boxing and weightlifting, a deadline of 2023 has been set for the UIPM to address International Olympic Committee concerns, with President Thomas Bach insisting the UIPM must "finalise its proposal for the replacement of horse riding and for the overall competition format".

Schormann is chairing a new UIPM working group established to determine a replacement fifth discipline to feature alongside fencing, swimming and the laser-run which combines running and shooting.

Raisner was found guilty by a UIPM Disciplinary Panel of violating Rule 4.6.8, under which a "pentathlete or team is disqualified for rapping or beating a horse and all other cases of cruelty and/or ill treatment of a horse".

She was ordered to attend a "coach education seminar" containing a "humane treatment of animals" module before returning to a UIPM competition, and was warned a repeat could lead to the removal of her UIPM Coaches Certification Programme credentials.

Schleu was found not guilty of excessive use of the whip and spur by the panel.